EXECUTE: Open preferences and select Struts->Customization preferences
ASSERT: There are no exceptions

Now it throws

java.lang.NullPointerException
at org.jboss.tools.struts.ui.preferences.LinkRecognizerPreferencePage.createContents(LinkRecognizerPreferencePage.java:47)
at org.eclipse.jface.preference.PreferencePage.createControl(PreferencePage.java:235)
at org.jboss.tools.common.model.ui.preferences.TabbedPreferencesPage.createContents(TabbedPreferencesPage.java:90)
at org.eclipse.jface.preference.PreferencePage.createControl(PreferencePage.java:235)
at org.eclipse.jface.preference.PreferenceDialog.createPageControl(PreferenceDialog.java:1468)
at org.eclipse.jface.preference.PreferenceDialog$14.run(PreferenceDialog.java:1225)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:37)
at org.eclipse.core.runtime.Platform.run(Platform.java:880)
at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:48)
at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:175)
at org.eclipse.jface.preference.PreferenceDialog.showPage(PreferenceDialog.java:1219)
at org.eclipse.ui.internal.dialogs.FilteredPreferenceDialog.showPage(FilteredPreferenceDialog.java:682)
at org.eclipse.jface.preference.PreferenceDialog$10.run(PreferenceDialog.java:702)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.jface.preference.PreferenceDialog$9.selectionChanged(PreferenceDialog.java:698)
at org.eclipse.jface.viewers.StructuredViewer$3.run(StructuredViewer.java:842)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:37)
at org.eclipse.core.runtime.Platform.run(Platform.java:880)
at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:48)
at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:175)
at org.eclipse.jface.viewers.StructuredViewer.firePostSelectionChanged(StructuredViewer.java:840)
at org.eclipse.jface.viewers.StructuredViewer.setSelection(StructuredViewer.java:1639)
at org.eclipse.jface.viewers.TreeViewer.setSelection(TreeViewer.java:1104)
at org.eclipse.jface.preference.PreferenceDialog.selectSavedItem(PreferenceDialog.java:1021)
at org.eclipse.ui.internal.dialogs.FilteredPreferenceDialog.selectSavedItem(FilteredPreferenceDialog.java:737)
at org.eclipse.jface.preference.PreferenceDialog$4.run(PreferenceDialog.java:369)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.jface.preference.PreferenceDialog.createContents(PreferenceDialog.java:365)
at org.eclipse.jface.window.Window.create(Window.java:431)
at org.eclipse.jface.dialogs.Dialog.create(Dialog.java:1089)
at org.eclipse.ui.internal.dialogs.WorkbenchPreferenceDialog.createDialogOn(WorkbenchPreferenceDialog.java:96)
at org.eclipse.ui.dialogs.PreferencesUtil.createPreferenceDialogOn(PreferencesUtil.java:97)
at org.eclipse.ui.internal.OpenPreferencesAction.run(OpenPreferencesAction.java:64)
at org.eclipse.jface.action.Action.runWithEvent(Action.java:498)
at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection(ActionContributionItem.java:583)
at org.eclipse.jface.action.ActionContributionItem.access$2(ActionContributionItem.java:500)
at org.eclipse.jface.action.ActionContributionItem$5.handleEvent(ActionContributionItem.java:411)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1158)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3401)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3033)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2384)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2348)
at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2200)
at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:495)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:288)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:490)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:113)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:193)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:386)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:179)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:549)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:504)
at org.eclipse.equinox.launcher.Main.run(Main.java:1236)
at org.eclipse.equinox.launcher.Main.main(Main.java:1212)