diff --git a/gui/src/main/java/io/bitsquare/gui/bitsquare.css b/gui/src/main/java/io/bitsquare/gui/bitsquare.css
index 9ee2658bee..aa8732dce5 100644
--- a/gui/src/main/java/io/bitsquare/gui/bitsquare.css
+++ b/gui/src/main/java/io/bitsquare/gui/bitsquare.css
@@ -7,7 +7,7 @@ new blue: 0f87c3
 new grey: 666666
 
 00abff
-orange webpage quotes : ff7f00
+orange web page quotes : ff7f00
 
 
 main bg grey: dddddd
@@ -679,7 +679,7 @@ textfield */
 }
 
 /* copied form modena.css text-input */
-#flowpane-checkboxes-bg {
+#flow-pane-checkboxes-bg {
     -fx-text-fill: -fx-text-inner-color;
     -fx-highlight-fill: derive(-fx-control-inner-background, -20%);
     -fx-highlight-text-fill: -fx-text-inner-color;
@@ -691,7 +691,7 @@ textfield */
     -fx-padding: 0.333333em 0.583em 0.333333em 0.583em; /* 4 7 4 7 */
 }
 
-#flowpane-checkboxes-non-editable-bg {
+#flow-pane-checkboxes-non-editable-bg {
     -fx-text-fill: -fx-text-inner-color;
     -fx-highlight-fill: derive(-fx-control-inner-background, -20%);
     -fx-highlight-text-fill: -fx-text-inner-color;
diff --git a/gui/src/main/java/io/bitsquare/gui/common/ViewFxException1.java b/gui/src/main/java/io/bitsquare/gui/common/ViewFxException1.java
new file mode 100644
index 0000000000..fd36f7ab9b
--- /dev/null
+++ b/gui/src/main/java/io/bitsquare/gui/common/ViewFxException1.java
@@ -0,0 +1,33 @@
+/*
+ * This file is part of Bitsquare.
+ *
+ * Bitsquare is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or (at
+ * your option) any later version.
+ *
+ * Bitsquare is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with Bitsquare. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package io.bitsquare.gui.common;
+
+import static java.lang.String.format;
+
+public class ViewFxException1 extends RuntimeException {
+
+    private static final long serialVersionUID = -6266047448442595372L;
+
+    public ViewFxException1(Throwable cause, String format, Object... args) {
+        super(format(format, args), cause);
+    }
+
+    public ViewFxException1(String format, Object... args) {
+        super(format(format, args));
+    }
+}
diff --git a/gui/src/main/java/io/bitsquare/gui/common/fxml/FxmlViewLoader.java b/gui/src/main/java/io/bitsquare/gui/common/fxml/FxmlViewLoader.java
index f24fb86962..9508a238a3 100644
--- a/gui/src/main/java/io/bitsquare/gui/common/fxml/FxmlViewLoader.java
+++ b/gui/src/main/java/io/bitsquare/gui/common/fxml/FxmlViewLoader.java
@@ -17,7 +17,7 @@
 
 package io.bitsquare.gui.common.fxml;
 
-import io.bitsquare.gui.common.ViewfxException;
+import io.bitsquare.gui.common.ViewFxException;
 import io.bitsquare.gui.common.view.FxmlView;
 import io.bitsquare.gui.common.view.View;
 import io.bitsquare.gui.common.view.ViewFactory;
@@ -76,13 +76,13 @@ public class FxmlViewLoader implements ViewLoader {
 
             URL fxmlUrl = viewClass.getClassLoader().getResource(resolvedLocation);
             if (fxmlUrl == null)
-                throw new ViewfxException(
+                throw new ViewFxException(
                         "Failed to load view class [%s] because FXML file at [%s] could not be loaded " +
                                 "as a classpath resource. Does it exist?", viewClass, specifiedLocation);
 
             return loadFromFxml(fxmlUrl);
         } catch (InstantiationException | IllegalAccessException ex) {
-            throw new ViewfxException(ex, "Failed to load view from class %s", viewClass);
+            throw new ViewFxException(ex, "Failed to load view from class %s", viewClass);
         }
     }
 
@@ -94,14 +94,14 @@ public class FxmlViewLoader implements ViewLoader {
             loader.load();
             Object controller = loader.getController();
             if (controller == null)
-                throw new ViewfxException("Failed to load view from FXML file at [%s]. " +
+                throw new ViewFxException("Failed to load view from FXML file at [%s]. " +
                         "Does it declare an fx:controller attribute?", fxmlUrl);
             if (!(controller instanceof View))
-                throw new ViewfxException("Controller of type [%s] loaded from FXML file at [%s] " +
+                throw new ViewFxException("Controller of type [%s] loaded from FXML file at [%s] " +
                         "does not implement [%s] as expected.", controller.getClass(), fxmlUrl, View.class);
             return (View) controller;
         } catch (IOException ex) {
-            throw new ViewfxException(ex, "Failed to load view from FXML file at [%s]", fxmlUrl);
+            throw new ViewFxException(ex, "Failed to load view from FXML file at [%s]", fxmlUrl);
         }
     }
 
diff --git a/gui/src/main/java/io/bitsquare/gui/common/model/Activatable.java b/gui/src/main/java/io/bitsquare/gui/common/model/Activatable.java
index 9d7a0afca0..18bf07cd02 100644
--- a/gui/src/main/java/io/bitsquare/gui/common/model/Activatable.java
+++ b/gui/src/main/java/io/bitsquare/gui/common/model/Activatable.java
@@ -24,7 +24,7 @@ public interface Activatable {
     void _deactivate();
 
 
-    Activatable NOOP_INSTANCE = new Activatable() {
+    Activatable NO_OP_INSTANCE = new Activatable() {
         @Override
         public void _activate() {
         }
diff --git a/gui/src/main/java/io/bitsquare/gui/common/view/ActivatableViewAndModel.java b/gui/src/main/java/io/bitsquare/gui/common/view/ActivatableViewAndModel.java
index a45a63ae74..9bec294a97 100644
--- a/gui/src/main/java/io/bitsquare/gui/common/view/ActivatableViewAndModel.java
+++ b/gui/src/main/java/io/bitsquare/gui/common/view/ActivatableViewAndModel.java
@@ -29,7 +29,7 @@ public abstract class ActivatableViewAndModel<R extends Node, M extends Activata
     }
 
     public ActivatableViewAndModel() {
-        this((M) Activatable.NOOP_INSTANCE);
+        this((M) Activatable.NO_OP_INSTANCE);
     }
 
     @Override
diff --git a/gui/src/main/java/io/bitsquare/gui/components/InfoDisplay.java b/gui/src/main/java/io/bitsquare/gui/components/InfoDisplay.java
index 5949078f20..1fb04e6c2a 100644
--- a/gui/src/main/java/io/bitsquare/gui/components/InfoDisplay.java
+++ b/gui/src/main/java/io/bitsquare/gui/components/InfoDisplay.java
@@ -126,7 +126,7 @@ public class InfoDisplay extends Parent {
         sceneProperty().addListener((ov, oldValue, newValue) -> {
             if (oldValue == null && newValue != null && newValue.getWindow() != null) {
                 newValue.getWindow().widthProperty().addListener(listener);
-                // localToScene does deliver 0 instead of the correct x position when scene propery gets set,
+                // localToScene does deliver 0 instead of the correct x position when scene property gets set,
                 // so we delay for 1 render cycle
                 UserThread.execute(() -> {
                     label.setVisible(true);
diff --git a/gui/src/main/java/io/bitsquare/gui/components/confidence/skin/ConfidenceProgressIndicatorSkin.java b/gui/src/main/java/io/bitsquare/gui/components/confidence/skin/ConfidenceProgressIndicatorSkin.java
index c004c6cba8..5325243137 100644
--- a/gui/src/main/java/io/bitsquare/gui/components/confidence/skin/ConfidenceProgressIndicatorSkin.java
+++ b/gui/src/main/java/io/bitsquare/gui/components/confidence/skin/ConfidenceProgressIndicatorSkin.java
@@ -64,7 +64,7 @@ public class ConfidenceProgressIndicatorSkin extends BehaviorSkinBase<Confidence
     /**
      * ************************************************************************
      * *
-     * UI Subcomponents                                                        *
+     * UI SubComponents                                                        *
      * *
      * ************************************************************************
      */
@@ -173,7 +173,7 @@ public class ConfidenceProgressIndicatorSkin extends BehaviorSkinBase<Confidence
             return StyleableProperties.PROGRESS_COLOR;
         }
     };
-    private boolean timelineNulled = false;
+    private boolean timeLineNulled = false;
 
     /**
      * ************************************************************************
@@ -192,8 +192,8 @@ public class ConfidenceProgressIndicatorSkin extends BehaviorSkinBase<Confidence
         InvalidationListener visibilityListener = new InvalidationListener() {
             @Override
             public void invalidated(Observable valueModel) {
-                if (getSkinnable().isIndeterminate() && timelineNulled && spinner == null) {
-                    timelineNulled = false;
+                if (getSkinnable().isIndeterminate() && timeLineNulled && spinner == null) {
+                    timeLineNulled = false;
                     spinner = new IndeterminateSpinner(
                             getSkinnable(), ConfidenceProgressIndicatorSkin.this,
                             spinEnabled.get(), progressColor.get());
@@ -204,7 +204,7 @@ public class ConfidenceProgressIndicatorSkin extends BehaviorSkinBase<Confidence
                     if (!(getSkinnable().impl_isTreeVisible() && getSkinnable().getScene() != null)) {
                         getChildren().remove(spinner);
                         spinner = null;
-                        timelineNulled = true;
+                        timeLineNulled = true;
                     }
                 }
             }
@@ -219,11 +219,11 @@ public class ConfidenceProgressIndicatorSkin extends BehaviorSkinBase<Confidence
                     if (getSkinnable().getScene() == null) {
                         getChildren().remove(spinner);
                         spinner = null;
-                        timelineNulled = true;
+                        timeLineNulled = true;
                     }
                 } else {
                     if (getSkinnable().getScene() != null && getSkinnable().isIndeterminate()) {
-                        timelineNulled = false;
+                        timeLineNulled = false;
                         spinner = new IndeterminateSpinner(
                                 getSkinnable(), ConfidenceProgressIndicatorSkin.this,
                                 spinEnabled.get(), progressColor.get());
diff --git a/gui/src/main/java/io/bitsquare/gui/components/paymentmethods/BlockChainForm.java b/gui/src/main/java/io/bitsquare/gui/components/paymentmethods/BlockChainForm.java
index c54b095c73..6a68ee8084 100644
--- a/gui/src/main/java/io/bitsquare/gui/components/paymentmethods/BlockChainForm.java
+++ b/gui/src/main/java/io/bitsquare/gui/components/paymentmethods/BlockChainForm.java
@@ -50,8 +50,7 @@ public class BlockChainForm extends PaymentMethodForm {
 
     public static int addFormForBuyer(GridPane gridPane, int gridRow, PaymentAccountContractData paymentAccountContractData) {
         addLabelTextFieldWithCopyIcon(gridPane, ++gridRow, "Cryptocurrency address:", ((BlockChainAccountContractData) paymentAccountContractData).getAddress());
-        if (paymentAccountContractData instanceof BlockChainAccountContractData &&
-                ((BlockChainAccountContractData) paymentAccountContractData).getPaymentId() != null)
+        if (((BlockChainAccountContractData) paymentAccountContractData).getPaymentId() != null)
             addLabelTextFieldWithCopyIcon(gridPane, ++gridRow, "Payment ID:", ((BlockChainAccountContractData) paymentAccountContractData).getPaymentId());
 
         return gridRow;
diff --git a/gui/src/main/java/io/bitsquare/gui/components/paymentmethods/OKPayForm.java b/gui/src/main/java/io/bitsquare/gui/components/paymentmethods/OKPayForm.java
index 689f3f6068..8b65bd414d 100644
--- a/gui/src/main/java/io/bitsquare/gui/components/paymentmethods/OKPayForm.java
+++ b/gui/src/main/java/io/bitsquare/gui/components/paymentmethods/OKPayForm.java
@@ -84,9 +84,9 @@ public class OKPayForm extends PaymentMethodForm {
         flowPane.setHgap(10);
 
         if (isEditable)
-            flowPane.setId("flowpane-checkboxes-bg");
+            flowPane.setId("flow-pane-checkboxes-bg");
         else
-            flowPane.setId("flowpane-checkboxes-non-editable-bg");
+            flowPane.setId("flow-pane-checkboxes-non-editable-bg");
 
         CurrencyUtil.getAllOKPayCurrencies().stream().forEach(e ->
         {
diff --git a/gui/src/main/java/io/bitsquare/gui/components/paymentmethods/SepaForm.java b/gui/src/main/java/io/bitsquare/gui/components/paymentmethods/SepaForm.java
index 58346d5530..0037f4d965 100644
--- a/gui/src/main/java/io/bitsquare/gui/components/paymentmethods/SepaForm.java
+++ b/gui/src/main/java/io/bitsquare/gui/components/paymentmethods/SepaForm.java
@@ -164,9 +164,9 @@ public class SepaForm extends PaymentMethodForm {
         flowPane.setHgap(10);
 
         if (isEditable)
-            flowPane.setId("flowpane-checkboxes-bg");
+            flowPane.setId("flow-pane-checkboxes-bg");
         else
-            flowPane.setId("flowpane-checkboxes-non-editable-bg");
+            flowPane.setId("flow-pane-checkboxes-non-editable-bg");
 
         dataProvider.stream().forEach(country ->
         {
@@ -255,7 +255,8 @@ public class SepaForm extends PaymentMethodForm {
         ibanField.setMouseTransparent(false);
         TextField bicField = addLabelTextField(gridPane, ++gridRow, "BIC/SWIFT:", sepaAccount.getBic()).second;
         bicField.setMouseTransparent(false);
-        addLabelTextField(gridPane, ++gridRow, "Location of Bank:", sepaAccount.getCountry().name);
+        addLabelTextField(gridPane, ++gridRow, "Location of Bank:",
+                sepaAccount.getCountry() != null ? sepaAccount.getCountry().name : "");
         addLabelTextField(gridPane, ++gridRow, "Currency:", sepaAccount.getSingleTradeCurrency().getNameAndCode());
         String countries;
         Tooltip tooltip = null;
diff --git a/gui/src/main/java/io/bitsquare/gui/components/processbar/ProcessStepBarSkin.java b/gui/src/main/java/io/bitsquare/gui/components/processbar/ProcessStepBarSkin.java
index f3a5ce47db..ff34a64bd8 100644
--- a/gui/src/main/java/io/bitsquare/gui/components/processbar/ProcessStepBarSkin.java
+++ b/gui/src/main/java/io/bitsquare/gui/components/processbar/ProcessStepBarSkin.java
@@ -154,6 +154,7 @@ class ProcessStepBarSkin<T> extends BehaviorSkinBase<ProcessStepBar<T>, Behavior
         }
 
         public void open() {
+            //noinspection SuspiciousNameCombination,SuspiciousNameCombination
             BorderStroke borderStroke = new BorderStroke(Colors.LIGHT_GREY, BorderStrokeStyle.SOLID, null,
                     new BorderWidths(borderWidth, borderWidth, borderWidth, borderWidth), Insets.EMPTY);
             this.setBorder(new Border(borderStroke));
@@ -161,6 +162,7 @@ class ProcessStepBarSkin<T> extends BehaviorSkinBase<ProcessStepBar<T>, Behavior
         }
 
         public void current() {
+            //noinspection SuspiciousNameCombination,SuspiciousNameCombination
             BorderStroke borderStroke = new BorderStroke(Colors.GREEN, BorderStrokeStyle.SOLID, null,
                     new BorderWidths(borderWidth, borderWidth, borderWidth, borderWidth), Insets.EMPTY);
             this.setBorder(new Border(borderStroke));
@@ -168,6 +170,7 @@ class ProcessStepBarSkin<T> extends BehaviorSkinBase<ProcessStepBar<T>, Behavior
         }
 
         public void past() {
+            //noinspection SuspiciousNameCombination,SuspiciousNameCombination
             BorderStroke borderStroke = new BorderStroke(Color.valueOf("#444444"), BorderStrokeStyle.SOLID, null,
                     new BorderWidths(borderWidth, borderWidth, borderWidth, borderWidth), Insets.EMPTY);
             this.setBorder(new Border(borderStroke));
diff --git a/gui/src/main/java/io/bitsquare/gui/main/MainView.java b/gui/src/main/java/io/bitsquare/gui/main/MainView.java
index 6ca54fff49..0be2f8ed67 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/MainView.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/MainView.java
@@ -464,13 +464,11 @@ public class MainView extends InitializableView<StackPane, MainViewModel> {
             p2PNetworkIcon.setOpacity(1);
         });
 
-        AnchorPane footerContainer = new AnchorPane(separator, blockchainSyncBox, versionLabel, p2PNetworkLabel, p2PNetworkIcon) {{
+        return new AnchorPane(separator, blockchainSyncBox, versionLabel, p2PNetworkLabel, p2PNetworkIcon) {{
             setId("footer-pane");
             setMinHeight(30);
             setMaxHeight(30);
         }};
-
-        return footerContainer;
     }
 
     private void setupNotificationIcon(Pane buttonHolder) {
diff --git a/gui/src/main/java/io/bitsquare/gui/main/MainViewModel.java b/gui/src/main/java/io/bitsquare/gui/main/MainViewModel.java
index 068adac3a3..f185542f02 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/MainViewModel.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/MainViewModel.java
@@ -91,9 +91,9 @@ public class MainViewModel implements ViewModel {
     private final Preferences preferences;
     private final AlertManager alertManager;
     private final WalletPasswordPopup walletPasswordPopup;
-    private NotificationCenter notificationCenter;
-    private TacPopup tacPopup;
-    private Navigation navigation;
+    private final NotificationCenter notificationCenter;
+    private final TacPopup tacPopup;
+    private final Navigation navigation;
     private final BSFormatter formatter;
 
     // BTC network
@@ -129,13 +129,13 @@ public class MainViewModel implements ViewModel {
     final StringProperty p2PNetworkLabelId = new SimpleStringProperty("footer-pane");
 
     private MonadicBinding<Boolean> allServicesDone, tradesAndUIReady;
-    private MarketPriceFeed marketPriceFeed;
+    private final MarketPriceFeed marketPriceFeed;
     private final User user;
     private int numBTCPeers = 0;
     private Timer checkForBtcSyncStateTimer;
     private ChangeListener<Number> numConnectedPeersListener, btcNumPeersListener;
-    private java.util.Timer numberofBtcPeersTimer;
-    private java.util.Timer numberofP2PNetworkPeersTimer;
+    private java.util.Timer numberOfBtcPeersTimer;
+    private java.util.Timer numberOfP2PNetworkPeersTimer;
     private Timer startupTimeout;
     private final Map<String, Subscription> disputeIsClosedSubscriptionsMap = new HashMap<>();
 
@@ -325,9 +325,9 @@ public class MainViewModel implements ViewModel {
         btcNumPeersListener = (observable, oldValue, newValue) -> {
             if ((int) oldValue > 0 && (int) newValue == 0) {
                 // give a bit of tolerance
-                if (numberofBtcPeersTimer != null)
-                    numberofBtcPeersTimer.cancel();
-                numberofBtcPeersTimer = UserThread.runAfter(() -> {
+                if (numberOfBtcPeersTimer != null)
+                    numberOfBtcPeersTimer.cancel();
+                numberOfBtcPeersTimer = UserThread.runAfter(() -> {
                     if (walletService.numPeersProperty().get() == 0) {
                         walletServiceErrorMsg.set("You lost the connection to all bitcoin network peers.\n" +
                                 "Maybe you lost your internet connection or your computer was in hibernate/sleep mode.");
@@ -517,9 +517,9 @@ public class MainViewModel implements ViewModel {
         numConnectedPeersListener = (observable, oldValue, newValue) -> {
             if ((int) oldValue > 0 && (int) newValue == 0) {
                 // give a bit of tolerance
-                if (numberofP2PNetworkPeersTimer != null)
-                    numberofP2PNetworkPeersTimer.cancel();
-                numberofP2PNetworkPeersTimer = UserThread.runAfter(() -> {
+                if (numberOfP2PNetworkPeersTimer != null)
+                    numberOfP2PNetworkPeersTimer.cancel();
+                numberOfP2PNetworkPeersTimer = UserThread.runAfter(() -> {
                     if (p2PService.getNumConnectedPeers().get() == 0) {
                         p2PNetworkWarnMsg.set("You lost the connection to all P2P network peers.\n" +
                                 "Maybe you lost your internet connection or your computer was in hibernate/sleep mode.");
diff --git a/gui/src/main/java/io/bitsquare/gui/main/account/arbitratorregistration/ArbitratorRegistrationViewModel.java b/gui/src/main/java/io/bitsquare/gui/main/account/arbitratorregistration/ArbitratorRegistrationViewModel.java
index 9c0732f939..5f5b617da2 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/account/arbitratorregistration/ArbitratorRegistrationViewModel.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/account/arbitratorregistration/ArbitratorRegistrationViewModel.java
@@ -79,7 +79,7 @@ class ArbitratorRegistrationViewModel extends ActivatableViewModel {
                 Arbitrator myRegisteredArbitrator = user.getRegisteredArbitrator();
                 myArbitratorProperty.set(myRegisteredArbitrator);
 
-                // We don't reset the languages in case of revokation, as its likely that the arbitrator will use the same again when he re-activate 
+                // We don't reset the languages in case of revocation, as its likely that the arbitrator will use the same again when he re-activate 
                 // registration later
                 if (myRegisteredArbitrator != null)
                     languageCodes.setAll(myRegisteredArbitrator.getLanguageCodes());
diff --git a/gui/src/main/java/io/bitsquare/gui/main/account/content/seedwords/SeedWordsView.java b/gui/src/main/java/io/bitsquare/gui/main/account/content/seedwords/SeedWordsView.java
index 86f6dfb102..89845b029c 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/account/content/seedwords/SeedWordsView.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/account/content/seedwords/SeedWordsView.java
@@ -130,8 +130,12 @@ public class SeedWordsView extends ActivatableView<GridPane, Void> {
             Wallet wallet = walletService.getWallet();
             KeyCrypter keyCrypter = wallet.getKeyCrypter();
             keyChainSeed = wallet.getKeyChainSeed();
-            DeterministicSeed decryptedSeed = keyChainSeed.decrypt(keyCrypter, "", aesKey);
-            showSeedScreen(decryptedSeed);
+            if (keyCrypter != null) {
+                DeterministicSeed decryptedSeed = keyChainSeed.decrypt(keyCrypter, "", aesKey);
+                showSeedScreen(decryptedSeed);
+            } else {
+                log.warn("keyCrypter is null");
+            }
         }).show();
     }
 
diff --git a/gui/src/main/java/io/bitsquare/gui/main/account/settings/AccountSettingsView.java b/gui/src/main/java/io/bitsquare/gui/main/account/settings/AccountSettingsView.java
index 8585587347..c4b4d09fbb 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/account/settings/AccountSettingsView.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/account/settings/AccountSettingsView.java
@@ -56,7 +56,7 @@ public class AccountSettingsView extends ActivatableViewAndModel {
     @FXML
     private AnchorPane content;
 
-    private Class<? extends View> selecteedViewClass;
+    private Class<? extends View> selectedViewClass;
 
     @Inject
     private AccountSettingsView(CachingViewLoader viewLoader, Navigation navigation) {
@@ -97,8 +97,8 @@ public class AccountSettingsView extends ActivatableViewAndModel {
                 viewPath.size() == 2 && viewPath.indexOf(AccountView.class) == 1) {
             navigation.navigateTo(MainView.class, AccountView.class, AccountSettingsView.class, PaymentAccountView.class);
         } else if (viewPath.size() == 4 && viewPath.indexOf(AccountSettingsView.class) == 2) {
-            selecteedViewClass = viewPath.get(3);
-            loadView(selecteedViewClass);
+            selectedViewClass = viewPath.get(3);
+            loadView(selectedViewClass);
         }
     }
 
@@ -125,7 +125,7 @@ public class AccountSettingsView extends ActivatableViewAndModel {
     }
 
     public Class<? extends View> getSelectedViewClass() {
-        return selecteedViewClass;
+        return selectedViewClass;
     }
 
 }
@@ -135,8 +135,8 @@ class MenuItem extends ToggleButton {
 
     private final ChangeListener<Boolean> selectedPropertyChangeListener;
     private final ChangeListener<Boolean> disablePropertyChangeListener;
-    private Navigation navigation;
-    private Class<? extends View> viewClass;
+    private final Navigation navigation;
+    private final Class<? extends View> viewClass;
 
     MenuItem(Navigation navigation, ToggleGroup toggleGroup, String title, Class<? extends View> viewClass, AwesomeIcon awesomeIcon) {
         this.navigation = navigation;
diff --git a/gui/src/main/java/io/bitsquare/gui/main/debug/DebugView.java b/gui/src/main/java/io/bitsquare/gui/main/debug/DebugView.java
index 733e95fe6f..e5627c51ad 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/debug/DebugView.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/debug/DebugView.java
@@ -65,7 +65,7 @@ public class DebugView extends InitializableView {
                         OfferAvailabilityProtocol.class,
                         SendOfferAvailabilityRequest.class,
                         ProcessOfferAvailabilityResponse.class,
-                        Boolean.class, /* used as seperator*/
+                        Boolean.class, /* used as separator*/
 
                         
                         /*---- Protocol ----*/
@@ -74,7 +74,7 @@ public class DebugView extends InitializableView {
                         CreateOfferFeeTx.class,
                         AddOfferToRemoteOfferBook.class,
                         BroadcastCreateOfferFeeTx.class,
-                        Boolean.class, /* used as seperator*/
+                        Boolean.class, /* used as separator*/
 
                         
                         /*---- Protocol ----*/
@@ -98,7 +98,7 @@ public class DebugView extends InitializableView {
                         SignAndFinalizePayoutTx.class,
                         SendPayoutTxFinalizedMessage.class,
                         BroadcastAfterLockTime.class,
-                        Boolean.class, /* used as seperator*/
+                        Boolean.class, /* used as separator*/
                         
 
                         /*---- Protocol ----*/
@@ -123,7 +123,7 @@ public class DebugView extends InitializableView {
 
                         ProcessPayoutTxFinalizedMessage.class,
                         BroadcastAfterLockTime.class,
-                        Boolean.class /* used as seperator*/
+                        Boolean.class /* used as separator*/
                 )
         );
         final ObservableList<Class> items2 = FXCollections.observableArrayList(Arrays.asList(
@@ -149,7 +149,7 @@ public class DebugView extends InitializableView {
                         SignAndFinalizePayoutTx.class,
                         SendPayoutTxFinalizedMessage.class,
                         BroadcastAfterLockTime.class,
-                        Boolean.class, /* used as seperator*/
+                        Boolean.class, /* used as separator*/
                         
                         
                          /*---- Protocol ----*/
@@ -173,7 +173,7 @@ public class DebugView extends InitializableView {
 
                         ProcessPayoutTxFinalizedMessage.class,
                         BroadcastAfterLockTime.class,
-                        Boolean.class /* used as seperator*/
+                        Boolean.class /* used as separator*/
                 )
         );
 
diff --git a/gui/src/main/java/io/bitsquare/gui/main/disputes/DisputesView.fxml b/gui/src/main/java/io/bitsquare/gui/main/disputes/DisputesView.fxml
index 85c1b34b6a..56f85ca61b 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/disputes/DisputesView.fxml
+++ b/gui/src/main/java/io/bitsquare/gui/main/disputes/DisputesView.fxml
@@ -26,6 +26,6 @@
          AnchorPane.topAnchor="0.0"
          xmlns:fx="http://javafx.com/fxml">
 
-    <Tab fx:id="tradersDisputesTab" text="Support tickets" closable="false"></Tab>
+    <Tab fx:id="tradersDisputesTab" text="Support tickets" closable="false"/>
 
 </TabPane>
diff --git a/gui/src/main/java/io/bitsquare/gui/main/disputes/trader/TraderDisputeView.java b/gui/src/main/java/io/bitsquare/gui/main/disputes/trader/TraderDisputeView.java
index 5d5469f96c..d4971a6de8 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/disputes/trader/TraderDisputeView.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/disputes/trader/TraderDisputeView.java
@@ -228,7 +228,8 @@ public class TraderDisputeView extends ActivatableView<VBox, Void> {
                 hideSendMsgInfo(timer);
             }
         };
-        disputeDirectMessage.arrivedProperty().addListener(arrivedPropertyListener);
+        if (disputeDirectMessage.arrivedProperty() != null)
+            disputeDirectMessage.arrivedProperty().addListener(arrivedPropertyListener);
         storedInMailboxPropertyListener = (observable, oldValue, newValue) -> {
             if (newValue) {
                 sendMsgInfoLabel.setVisible(true);
diff --git a/gui/src/main/java/io/bitsquare/gui/main/funds/FundsView.fxml b/gui/src/main/java/io/bitsquare/gui/main/funds/FundsView.fxml
index 8164543468..2936e46cd3 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/funds/FundsView.fxml
+++ b/gui/src/main/java/io/bitsquare/gui/main/funds/FundsView.fxml
@@ -24,7 +24,7 @@
          AnchorPane.topAnchor="0.0"
          xmlns:fx="http://javafx.com/fxml">
 
-    <Tab fx:id="reservedTab" text="Reserved/Locked funds" closable="false"></Tab>
+    <Tab fx:id="reservedTab" text="Reserved/Locked funds" closable="false"/>
     <Tab fx:id="withdrawalTab" text="Available for withdrawal" closable="false"/>
     <Tab fx:id="transactionsTab" text="Transactions" closable="false"/>
 
diff --git a/gui/src/main/java/io/bitsquare/gui/main/markets/charts/MarketsChartsView.java b/gui/src/main/java/io/bitsquare/gui/main/markets/charts/MarketsChartsView.java
index 9adeb1f471..7e35cc60be 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/markets/charts/MarketsChartsView.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/markets/charts/MarketsChartsView.java
@@ -55,7 +55,7 @@ public class MarketsChartsView extends ActivatableViewAndModel<VBox, MarketsChar
     private NumberAxis xAxis, yAxis;
     XYChart.Series seriesBuy, seriesSell;
     private final ListChangeListener<OfferBookListItem> changeListener;
-    private Navigation navigation;
+    private final Navigation navigation;
     private final BSFormatter formatter;
     private TableView<Offer> buyOfferTableView;
     private TableView<Offer> sellOfferTableView;
diff --git a/gui/src/main/java/io/bitsquare/gui/main/markets/charts/MarketsChartsViewModel.java b/gui/src/main/java/io/bitsquare/gui/main/markets/charts/MarketsChartsViewModel.java
index 53a9d9545c..7139266602 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/markets/charts/MarketsChartsViewModel.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/markets/charts/MarketsChartsViewModel.java
@@ -42,7 +42,7 @@ class MarketsChartsViewModel extends ActivatableViewModel {
 
     private final OfferBook offerBook;
     private final Preferences preferences;
-    private MarketPriceFeed marketPriceFeed;
+    private final MarketPriceFeed marketPriceFeed;
 
     final ObjectProperty<TradeCurrency> tradeCurrency = new SimpleObjectProperty<>(CurrencyUtil.getDefaultTradeCurrency());
     private final List<XYChart.Data> buyData = new ArrayList();
diff --git a/gui/src/main/java/io/bitsquare/gui/main/notifications/NotificationCenter.java b/gui/src/main/java/io/bitsquare/gui/main/notifications/NotificationCenter.java
index 2cb5f0009e..0cabf64cee 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/notifications/NotificationCenter.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/notifications/NotificationCenter.java
@@ -48,10 +48,10 @@ public class NotificationCenter {
     // Instance fields
     ///////////////////////////////////////////////////////////////////////////////////////////
 
-    private TradeManager tradeManager;
-    private DisputeManager disputeManager;
-    private Preferences preferences;
-    private Navigation navigation;
+    private final TradeManager tradeManager;
+    private final DisputeManager disputeManager;
+    private final Preferences preferences;
+    private final Navigation navigation;
 
     private final Map<String, Subscription> disputeStateSubscriptionsMap = new HashMap<>();
     private final Map<String, Subscription> tradeStateSubscriptionsMap = new HashMap<>();
@@ -126,6 +126,7 @@ public class NotificationCenter {
     // Setter/Getter
     ///////////////////////////////////////////////////////////////////////////////////////////
 
+    @org.jetbrains.annotations.Nullable
     public String getSelectedTradeId() {
         return selectedTradeId;
     }
diff --git a/gui/src/main/java/io/bitsquare/gui/main/offer/OfferView.java b/gui/src/main/java/io/bitsquare/gui/main/offer/OfferView.java
index 2f94dd218d..feda8e68b9 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/offer/OfferView.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/offer/OfferView.java
@@ -52,7 +52,7 @@ public abstract class OfferView extends ActivatableView<TabPane, Void> {
 
     private final ViewLoader viewLoader;
     private final Navigation navigation;
-    private MarketPriceFeed marketPriceFeed;
+    private final MarketPriceFeed marketPriceFeed;
     private final Offer.Direction direction;
     private Tab takeOfferTab, createOfferTab, offerBookTab;
     private TradeCurrency tradeCurrency;
@@ -94,7 +94,7 @@ public abstract class OfferView extends ActivatableView<TabPane, Void> {
                 }
             }
         };
-        tabListChangeListener = (ListChangeListener<Tab>) change -> {
+        tabListChangeListener = change -> {
             change.next();
             List<? extends Tab> removedTabs = change.getRemoved();
             if (removedTabs.size() == 1) {
diff --git a/gui/src/main/java/io/bitsquare/gui/main/offer/createoffer/CreateOfferDataModel.java b/gui/src/main/java/io/bitsquare/gui/main/offer/createoffer/CreateOfferDataModel.java
index 7cf78e9db1..3a886ab13f 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/offer/createoffer/CreateOfferDataModel.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/offer/createoffer/CreateOfferDataModel.java
@@ -70,9 +70,9 @@ class CreateOfferDataModel extends ActivatableDataModel {
     private final User user;
     private final KeyRing keyRing;
     private final P2PService p2PService;
-    private MarketPriceFeed marketPriceFeed;
+    private final MarketPriceFeed marketPriceFeed;
     private final WalletPasswordPopup walletPasswordPopup;
-    private BlockchainService blockchainService;
+    private final BlockchainService blockchainService;
     private final BSFormatter formatter;
     private final String offerId;
     private final AddressEntry addressEntry;
diff --git a/gui/src/main/java/io/bitsquare/gui/main/offer/createoffer/CreateOfferView.java b/gui/src/main/java/io/bitsquare/gui/main/offer/createoffer/CreateOfferView.java
index 2838f276ca..59bd8479f2 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/offer/createoffer/CreateOfferView.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/offer/createoffer/CreateOfferView.java
@@ -110,7 +110,7 @@ public class CreateOfferView extends ActivatableViewAndModel<AnchorPane, CreateO
 
     private EventHandler<ActionEvent> currencyComboBoxSelectionHandler;
     private int gridRow = 0;
-    private Preferences preferences;
+    private final Preferences preferences;
 
 
     ///////////////////////////////////////////////////////////////////////////////////////////
@@ -213,7 +213,7 @@ public class CreateOfferView extends ActivatableViewAndModel<AnchorPane, CreateO
     private void onPlaceOffer() {
         if (model.isBootstrapped()) {
             Offer offer = model.createAndGetOffer();
-            String id = "CreatOfferConfirmation";
+            String id = "CreateOfferConfirmation";
             if (preferences.showAgain(id)) {
                 offerDetailsPopup.onPlaceOffer(model::onPlaceOffer)
                         .dontShowAgainId(id)
diff --git a/gui/src/main/java/io/bitsquare/gui/main/offer/createoffer/CreateOfferViewModel.java b/gui/src/main/java/io/bitsquare/gui/main/offer/createoffer/CreateOfferViewModel.java
index dc6321531b..459bd1f684 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/offer/createoffer/CreateOfferViewModel.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/offer/createoffer/CreateOfferViewModel.java
@@ -118,7 +118,7 @@ class CreateOfferViewModel extends ActivatableWithDataModel<CreateOfferDataModel
         paymentLabel = BSResources.get("createOffer.fundsBox.paymentLabel", dataModel.getOfferId());
 
         if (dataModel.getAddressEntry() != null) {
-            addressAsString = dataModel.getAddressEntry().getAddress().toString();
+            addressAsString = dataModel.getAddressEntry().getAddressString();
             address.set(dataModel.getAddressEntry().getAddress());
         }
         createListeners();
diff --git a/gui/src/main/java/io/bitsquare/gui/main/offer/offerbook/OfferBookViewModel.java b/gui/src/main/java/io/bitsquare/gui/main/offer/offerbook/OfferBookViewModel.java
index ae33237998..aa0e560788 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/offer/offerbook/OfferBookViewModel.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/offer/offerbook/OfferBookViewModel.java
@@ -53,7 +53,7 @@ class OfferBookViewModel extends ActivatableViewModel {
     private final OfferBook offerBook;
     private final Preferences preferences;
     private final P2PService p2PService;
-    private MarketPriceFeed marketPriceFeed;
+    private final MarketPriceFeed marketPriceFeed;
     final BSFormatter formatter;
 
     private final FilteredList<OfferBookListItem> filteredItems;
@@ -168,8 +168,7 @@ class OfferBookViewModel extends ActivatableViewModel {
     }
 
     public ObservableList<TradeCurrency> getTradeCurrencies() {
-        ObservableList<TradeCurrency> list = preferences.getTradeCurrenciesAsObservable();
-        return list;
+        return preferences.getTradeCurrenciesAsObservable();
     }
 
     boolean isBootstrapped() {
diff --git a/gui/src/main/java/io/bitsquare/gui/main/offer/takeoffer/TakeOfferDataModel.java b/gui/src/main/java/io/bitsquare/gui/main/offer/takeoffer/TakeOfferDataModel.java
index 1b4a94a5ce..e637c22922 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/offer/takeoffer/TakeOfferDataModel.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/offer/takeoffer/TakeOfferDataModel.java
@@ -68,9 +68,9 @@ class TakeOfferDataModel extends ActivatableDataModel {
     private final User user;
     private final WalletPasswordPopup walletPasswordPopup;
     private final Preferences preferences;
-    private MarketPriceFeed marketPriceFeed;
-    private BlockchainService blockchainService;
-    private BSFormatter formatter;
+    private final MarketPriceFeed marketPriceFeed;
+    private final BlockchainService blockchainService;
+    private final BSFormatter formatter;
 
     private final Coin offerFeeAsCoin;
     private final Coin networkFeeAsCoin;
@@ -305,7 +305,6 @@ class TakeOfferDataModel extends ActivatableDataModel {
 
     void calculateVolume() {
         if (offer != null &&
-                offer.getPrice() != null &&
                 amountAsCoin.get() != null &&
                 !amountAsCoin.get().isZero()) {
             volumeAsFiat.set(new ExchangeRate(offer.getPrice()).coinToFiat(amountAsCoin.get()));
@@ -330,7 +329,7 @@ class TakeOfferDataModel extends ActivatableDataModel {
 
     boolean isMinAmountLessOrEqualAmount() {
         //noinspection SimplifiableIfStatement
-        if (offer != null && offer.getMinAmount() != null && amountAsCoin.get() != null)
+        if (offer != null && amountAsCoin.get() != null)
             return !offer.getMinAmount().isGreaterThan(amountAsCoin.get());
         return true;
     }
diff --git a/gui/src/main/java/io/bitsquare/gui/main/offer/takeoffer/TakeOfferView.java b/gui/src/main/java/io/bitsquare/gui/main/offer/takeoffer/TakeOfferView.java
index 341d0bd680..c48ac6e506 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/offer/takeoffer/TakeOfferView.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/offer/takeoffer/TakeOfferView.java
@@ -72,7 +72,7 @@ public class TakeOfferView extends ActivatableViewAndModel<AnchorPane, TakeOffer
     private final Navigation navigation;
     private final BSFormatter formatter;
     private final OfferDetailsPopup offerDetailsPopup;
-    private Preferences preferences;
+    private final Preferences preferences;
     private ScrollPane scrollPane;
     private GridPane gridPane;
     private ImageView imageView;
diff --git a/gui/src/main/java/io/bitsquare/gui/main/offer/takeoffer/TakeOfferViewModel.java b/gui/src/main/java/io/bitsquare/gui/main/offer/takeoffer/TakeOfferViewModel.java
index ecd6645bd6..6b581eade3 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/offer/takeoffer/TakeOfferViewModel.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/offer/takeoffer/TakeOfferViewModel.java
@@ -48,7 +48,7 @@ import static javafx.beans.binding.Bindings.createStringBinding;
 
 class TakeOfferViewModel extends ActivatableWithDataModel<TakeOfferDataModel> implements ViewModel {
     private final BtcValidator btcValidator;
-    private P2PService p2PService;
+    private final P2PService p2PService;
     final BSFormatter formatter;
 
     private String amountRange;
@@ -161,7 +161,7 @@ class TakeOfferViewModel extends ActivatableWithDataModel<TakeOfferDataModel> im
 
         checkNotNull(dataModel.getAddressEntry(), "dataModel.getAddressEntry() must not be null");
 
-        addressAsString = dataModel.getAddressEntry().getAddress().toString();
+        addressAsString = dataModel.getAddressEntry().getAddressString();
         address.set(dataModel.getAddressEntry().getAddress());
 
         offerErrorListener = (observable, oldValue, newValue) -> {
diff --git a/gui/src/main/java/io/bitsquare/gui/main/popups/OfferDetailsPopup.java b/gui/src/main/java/io/bitsquare/gui/main/popups/OfferDetailsPopup.java
index 20cc2cc9a8..bc93b4c5b9 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/popups/OfferDetailsPopup.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/popups/OfferDetailsPopup.java
@@ -52,7 +52,7 @@ public class OfferDetailsPopup extends Popup {
     private final BSFormatter formatter;
     protected final Preferences preferences;
     private final User user;
-    private KeyRing keyRing;
+    private final KeyRing keyRing;
     private final Navigation navigation;
     private Offer offer;
     private Coin tradeAmount;
diff --git a/gui/src/main/java/io/bitsquare/gui/main/popups/PopupManager.java b/gui/src/main/java/io/bitsquare/gui/main/popups/PopupManager.java
index 7bff92e8c3..0da8417347 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/popups/PopupManager.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/popups/PopupManager.java
@@ -8,7 +8,7 @@ import java.util.concurrent.LinkedBlockingQueue;
 
 class PopupManager {
     private static final Logger log = LoggerFactory.getLogger(PopupManager.class);
-    private static Queue<Popup> popups = new LinkedBlockingQueue<>(3);
+    private static final Queue<Popup> popups = new LinkedBlockingQueue<>(3);
     private static Popup displayedPopup;
 
     static void queueForDisplay(Popup popup) {
diff --git a/gui/src/main/java/io/bitsquare/gui/main/popups/TacPopup.java b/gui/src/main/java/io/bitsquare/gui/main/popups/TacPopup.java
index c0bf6cdca0..fe1cca62d3 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/popups/TacPopup.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/popups/TacPopup.java
@@ -12,7 +12,7 @@ import java.util.concurrent.TimeUnit;
 
 public class TacPopup extends Popup {
     private static final Logger log = LoggerFactory.getLogger(TacPopup.class);
-    private Preferences preferences;
+    private final Preferences preferences;
 
     @Inject
     public TacPopup(Preferences preferences) {
diff --git a/gui/src/main/java/io/bitsquare/gui/main/popups/TradeDetailsPopup.java b/gui/src/main/java/io/bitsquare/gui/main/popups/TradeDetailsPopup.java
index 396b3abcfb..14c5f294f8 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/popups/TradeDetailsPopup.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/popups/TradeDetailsPopup.java
@@ -45,7 +45,7 @@ public class TradeDetailsPopup extends Popup {
     protected static final Logger log = LoggerFactory.getLogger(TradeDetailsPopup.class);
 
     private final BSFormatter formatter;
-    private DisputeManager disputeManager;
+    private final DisputeManager disputeManager;
     private Trade trade;
     private ChangeListener<Number> changeListener;
     private TextArea textArea;
diff --git a/gui/src/main/java/io/bitsquare/gui/main/portfolio/failedtrades/FailedTradesViewModel.java b/gui/src/main/java/io/bitsquare/gui/main/portfolio/failedtrades/FailedTradesViewModel.java
index 506a43a04f..5b0087b528 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/portfolio/failedtrades/FailedTradesViewModel.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/portfolio/failedtrades/FailedTradesViewModel.java
@@ -44,7 +44,7 @@ class FailedTradesViewModel extends ActivatableWithDataModel<FailedTradesDataMod
     }
 
     String getAmount(FailedTradesListItem item) {
-        if (item != null && item.getTrade() instanceof Trade)
+        if (item != null && item.getTrade() != null)
             return formatter.formatCoinWithCode(item.getTrade().getTradeAmount());
         else
             return "";
@@ -55,7 +55,7 @@ class FailedTradesViewModel extends ActivatableWithDataModel<FailedTradesDataMod
     }
 
     String getVolume(FailedTradesListItem item) {
-        if (item != null && item.getTrade() instanceof Trade)
+        if (item != null && item.getTrade() != null)
             return formatter.formatFiatWithCode(item.getTrade().getTradeVolume());
         else
             return "";
diff --git a/gui/src/main/java/io/bitsquare/gui/main/portfolio/pendingtrades/PendingTradesDataModel.java b/gui/src/main/java/io/bitsquare/gui/main/portfolio/pendingtrades/PendingTradesDataModel.java
index 63d7e5779b..d2face162e 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/portfolio/pendingtrades/PendingTradesDataModel.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/portfolio/pendingtrades/PendingTradesDataModel.java
@@ -72,7 +72,7 @@ public class PendingTradesDataModel extends ActivatableDataModel {
     public final DisputeManager disputeManager;
     private final Navigation navigation;
     private final WalletPasswordPopup walletPasswordPopup;
-    private NotificationCenter notificationCenter;
+    private final NotificationCenter notificationCenter;
 
     final ObservableList<PendingTradesListItem> list = FXCollections.observableArrayList();
     private final ListChangeListener<Trade> tradesListChangeListener;
@@ -351,36 +351,42 @@ public class PendingTradesDataModel extends ActivatableDataModel {
         } else {
             log.warn("depositTx is null");
         }
-        Transaction payoutTx = getTrade().getPayoutTx();
-        if (payoutTx != null) {
-            payoutTxSerialized = payoutTx.bitcoinSerialize();
-            payoutTxHashAsString = payoutTx.getHashAsString();
-        }
-
         Trade trade = getTrade();
-        Dispute dispute = new Dispute(disputeManager.getDisputeStorage(),
-                trade.getId(),
-                keyRing.getPubKeyRing().hashCode(), // traderId
-                trade.getOffer().getDirection() == Offer.Direction.BUY ? isOfferer : !isOfferer,
-                isOfferer,
-                keyRing.getPubKeyRing(),
-                trade.getDate(),
-                trade.getContract(),
-                trade.getContractHash(),
-                depositTxSerialized,
-                payoutTxSerialized,
-                depositTxHashAsString,
-                payoutTxHashAsString,
-                trade.getContractAsJson(),
-                trade.getOffererContractSignature(),
-                trade.getTakerContractSignature(),
-                user.getAcceptedArbitratorByAddress(trade.getArbitratorNodeAddress()).getPubKeyRing(),
-                isSupportTicket
-        );
+        if (trade != null) {
+            Transaction payoutTx = trade.getPayoutTx();
+            if (payoutTx != null) {
+                payoutTxSerialized = payoutTx.bitcoinSerialize();
+                payoutTxHashAsString = payoutTx.getHashAsString();
+            } else {
+                log.warn("payoutTx is null at doOpenDispute");
+            }
 
-        trade.setDisputeState(Trade.DisputeState.DISPUTE_REQUESTED);
-        disputeManager.sendOpenNewDisputeMessage(dispute);
-        navigation.navigateTo(MainView.class, DisputesView.class);
+            Dispute dispute = new Dispute(disputeManager.getDisputeStorage(),
+                    trade.getId(),
+                    keyRing.getPubKeyRing().hashCode(), // traderId
+                    trade.getOffer().getDirection() == Offer.Direction.BUY ? isOfferer : !isOfferer,
+                    isOfferer,
+                    keyRing.getPubKeyRing(),
+                    trade.getDate(),
+                    trade.getContract(),
+                    trade.getContractHash(),
+                    depositTxSerialized,
+                    payoutTxSerialized,
+                    depositTxHashAsString,
+                    payoutTxHashAsString,
+                    trade.getContractAsJson(),
+                    trade.getOffererContractSignature(),
+                    trade.getTakerContractSignature(),
+                    user.getAcceptedArbitratorByAddress(trade.getArbitratorNodeAddress()).getPubKeyRing(),
+                    isSupportTicket
+            );
+
+            trade.setDisputeState(Trade.DisputeState.DISPUTE_REQUESTED);
+            disputeManager.sendOpenNewDisputeMessage(dispute);
+            navigation.navigateTo(MainView.class, DisputesView.class);
+        } else {
+            log.warn("trade is null at doOpenDispute");
+        }
     }
 }
 
diff --git a/gui/src/main/java/io/bitsquare/gui/main/portfolio/pendingtrades/PendingTradesView.java b/gui/src/main/java/io/bitsquare/gui/main/portfolio/pendingtrades/PendingTradesView.java
index e698a70703..efb415c146 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/portfolio/pendingtrades/PendingTradesView.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/portfolio/pendingtrades/PendingTradesView.java
@@ -50,7 +50,7 @@ import javax.inject.Inject;
 public class PendingTradesView extends ActivatableViewAndModel<VBox, PendingTradesViewModel> {
 
     private final TradeDetailsPopup tradeDetailsPopup;
-    private BSFormatter formatter;
+    private final BSFormatter formatter;
     @FXML
     TableView<PendingTradesListItem> table;
     @FXML
diff --git a/gui/src/main/java/io/bitsquare/gui/main/portfolio/pendingtrades/PendingTradesViewModel.java b/gui/src/main/java/io/bitsquare/gui/main/portfolio/pendingtrades/PendingTradesViewModel.java
index 56467c13ca..343a6771ad 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/portfolio/pendingtrades/PendingTradesViewModel.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/portfolio/pendingtrades/PendingTradesViewModel.java
@@ -68,7 +68,7 @@ public class PendingTradesViewModel extends ActivatableWithDataModel<PendingTrad
     private final BtcAddressValidator btcAddressValidator;
 
     public final P2PService p2PService;
-    public User user;
+    public final User user;
 
     private final ObjectProperty<BuyerState> buyerState = new SimpleObjectProperty<>();
     private final ObjectProperty<SellerState> sellerState = new SimpleObjectProperty<>();
diff --git a/gui/src/main/java/io/bitsquare/gui/main/portfolio/pendingtrades/TradeSubView.java b/gui/src/main/java/io/bitsquare/gui/main/portfolio/pendingtrades/TradeSubView.java
index 6e6eb4c396..ac1cf0ea9f 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/portfolio/pendingtrades/TradeSubView.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/portfolio/pendingtrades/TradeSubView.java
@@ -166,7 +166,7 @@ public abstract class TradeSubView extends HBox {
 
     private void addLeftBox() {
         leftVBox = new VBox();
-        leftVBox.setSpacing(Layout.SPACING_VBOX);
+        leftVBox.setSpacing(Layout.SPACING_V_BOX);
         leftVBox.setMinWidth(290);
         getChildren().add(leftVBox);
     }
diff --git a/gui/src/main/java/io/bitsquare/gui/main/portfolio/pendingtrades/steps/buyer/BuyerStep2View.java b/gui/src/main/java/io/bitsquare/gui/main/portfolio/pendingtrades/steps/buyer/BuyerStep2View.java
index 68299a24c5..b66878aa1e 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/portfolio/pendingtrades/steps/buyer/BuyerStep2View.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/portfolio/pendingtrades/steps/buyer/BuyerStep2View.java
@@ -119,7 +119,7 @@ public class BuyerStep2View extends TradeStepView {
         addTradeInfoBlock();
 
         PaymentAccountContractData paymentAccountContractData = model.dataModel.getSellersPaymentAccountContractData();
-        String paymentMethodName = paymentAccountContractData.getPaymentMethodName();
+        String paymentMethodName = paymentAccountContractData != null ? paymentAccountContractData.getPaymentMethodName() : "";
         TitledGroupBg accountTitledGroupBg = addTitledGroupBg(gridPane, ++gridRow, 1,
                 "Start payment using " + BSResources.get(paymentAccountContractData.getPaymentMethodName()),
                 Layout.GROUP_DISTANCE);
diff --git a/gui/src/main/java/io/bitsquare/gui/main/portfolio/pendingtrades/steps/buyer/BuyerStep5View.java b/gui/src/main/java/io/bitsquare/gui/main/portfolio/pendingtrades/steps/buyer/BuyerStep5View.java
index de88587ee6..4348935920 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/portfolio/pendingtrades/steps/buyer/BuyerStep5View.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/portfolio/pendingtrades/steps/buyer/BuyerStep5View.java
@@ -98,9 +98,9 @@ public class BuyerStep5View extends TradeStepView {
         Tuple2<Label, TextField> fiatTradeAmountPair = addLabelTextField(gridPane, ++gridRow, getFiatTradeAmountLabel(), model.getFiatVolume());
         fiatTradeAmountLabel = fiatTradeAmountPair.first;
 
-        Tuple2<Label, TextField> feesPair = addLabelTextField(gridPane, ++gridRow, "Total fees paid:", model.getTotalFees());
+        addLabelTextField(gridPane, ++gridRow, "Total fees paid:", model.getTotalFees());
 
-        Tuple2<Label, TextField> securityDepositPair = addLabelTextField(gridPane, ++gridRow, "Refunded security deposit:", model.getSecurityDeposit());
+        addLabelTextField(gridPane, ++gridRow, "Refunded security deposit:", model.getSecurityDeposit());
 
         addTitledGroupBg(gridPane, ++gridRow, 2, "Withdraw your bitcoins", Layout.GROUP_DISTANCE);
         addLabelTextField(gridPane, gridRow, "Amount to withdraw:", model.getPayoutAmount(), Layout.FIRST_ROW_AND_GROUP_DISTANCE);
diff --git a/gui/src/main/java/io/bitsquare/gui/main/settings/preferences/PreferencesView.java b/gui/src/main/java/io/bitsquare/gui/main/settings/preferences/PreferencesView.java
index 3802fce55e..2827fe8157 100644
--- a/gui/src/main/java/io/bitsquare/gui/main/settings/preferences/PreferencesView.java
+++ b/gui/src/main/java/io/bitsquare/gui/main/settings/preferences/PreferencesView.java
@@ -48,7 +48,7 @@ public class PreferencesView extends ActivatableViewAndModel<GridPane, Preferenc
     private int gridRow = 0;
     //private InputTextField transactionFeeInputTextField;
     private ChangeListener<Boolean> transactionFeeFocusedListener;
-    private Preferences preferences;
+    private final Preferences preferences;
 
     @Inject
     public PreferencesView(PreferencesViewModel model, Preferences preferences) {
diff --git a/gui/src/main/java/io/bitsquare/gui/util/Layout.java b/gui/src/main/java/io/bitsquare/gui/util/Layout.java
index e280dcfb7b..c7ed71b111 100644
--- a/gui/src/main/java/io/bitsquare/gui/util/Layout.java
+++ b/gui/src/main/java/io/bitsquare/gui/util/Layout.java
@@ -23,8 +23,8 @@ public class Layout {
     public static final double FIRST_ROW_AND_GROUP_DISTANCE = GROUP_DISTANCE + FIRST_ROW_DISTANCE;
     public static final double PADDING_WINDOW = 20d;
     public static double PADDING = 10d;
-    public static double SPACING_HBOX = 10d;
-    public static final double SPACING_VBOX = 5d;
+    public static double SPACING_H_BOX = 10d;
+    public static final double SPACING_V_BOX = 5d;
     public static final double GRID_GAP = 5d;
     public static final double LIST_ROW_HEIGHT = 34;
 
diff --git a/gui/src/test/java/io/bitsquare/common/fxml/FxmlViewLoaderTests.java b/gui/src/test/java/io/bitsquare/common/fxml/FxmlViewLoaderTests.java
index 01b51ead67..1424259f43 100644
--- a/gui/src/test/java/io/bitsquare/common/fxml/FxmlViewLoaderTests.java
+++ b/gui/src/test/java/io/bitsquare/common/fxml/FxmlViewLoaderTests.java
@@ -17,7 +17,7 @@
 
 package io.bitsquare.common.fxml;
 
-import io.bitsquare.gui.common.ViewfxException;
+import io.bitsquare.gui.common.ViewFxException;
 import io.bitsquare.gui.common.fxml.FxmlViewLoader;
 import io.bitsquare.gui.common.view.*;
 import javafx.fxml.LoadException;
@@ -70,7 +70,7 @@ public class FxmlViewLoaderTests {
 
     @Test
     public void fxmlFileMissingFxControllerAttributeShouldThrow() {
-        thrown.expect(ViewfxException.class);
+        thrown.expect(ViewFxException.class);
         thrown.expectMessage("Does it declare an fx:controller attribute?");
         viewLoader.load(MissingFxController.class);
     }
@@ -93,7 +93,7 @@ public class FxmlViewLoaderTests {
 
     @Test
     public void malformedFxmlFileShouldThrow() {
-        thrown.expect(ViewfxException.class);
+        thrown.expect(ViewFxException.class);
         thrown.expectMessage("Failed to load view from FXML file");
         thrown.expectCause(instanceOf(LoadException.class));
         viewLoader.load(Malformed.class);
@@ -106,7 +106,7 @@ public class FxmlViewLoaderTests {
 
     @Test
     public void missingFxmlFileShouldThrow() {
-        thrown.expect(ViewfxException.class);
+        thrown.expect(ViewFxException.class);
         thrown.expectMessage("Does it exist?");
         viewLoader.load(MissingFxmlFile.class);
     }
@@ -118,7 +118,7 @@ public class FxmlViewLoaderTests {
 
     @Test
     public void customFxmlFileLocationShouldOverrideDefaultConvention() {
-        thrown.expect(ViewfxException.class);
+        thrown.expect(ViewFxException.class);
         thrown.expectMessage("Failed to load view class");
         thrown.expectMessage("CustomLocation");
         thrown.expectMessage("[unconventionally/located.fxml] could not be loaded");