java.lang.NullPointerException
        at org.jboss.tools.common.ui.preferences.SeverityPreferencePage.updateEnableBlock(SeverityPreferencePage.java:155)
        at org.jboss.tools.common.ui.preferences.SeverityPreferencePage.performOk(SeverityPreferencePage.java:138)
        at org.eclipse.jface.preference.PreferenceDialog$13.run(PreferenceDialog.java:964)
        at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
        at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:49)
        at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:175)
        at org.eclipse.jface.preference.PreferenceDialog.okPressed(PreferenceDialog.java:944)
        at org.eclipse.ui.internal.dialogs.FilteredPreferenceDialog.okPressed(FilteredPreferenceDialog.java:447)
        at org.eclipse.ui.internal.dialogs.WorkbenchPreferenceDialog.okPressed(WorkbenchPreferenceDialog.java:171)
        at org.eclipse.jface.preference.PreferenceDialog.buttonPressed(PreferenceDialog.java:233)
        at org.eclipse.jface.dialogs.Dialog$2.widgetSelected(Dialog.java:624)
        at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:240)
        at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
        at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1258)
        at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3588)
        at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3209)
        at org.eclipse.jface.window.Window.runEventLoop(Window.java:825)
        at org.eclipse.jface.window.Window.open(Window.java:801)
        at org.eclipse.ui.internal.dialogs.WorkbenchPreferenceDialog.open(WorkbenchPreferenceDialog.java:215)
        at org.eclipse.ui.internal.handlers.ShowPreferencePageHandler.execute(ShowPreferencePageHandler.java:54)
        at org.eclipse.ui.internal.handlers.HandlerProxy.execute(HandlerProxy.java:293)
        at org.eclipse.core.commands.Command.executeWithChecks(Command.java:476)
        at org.eclipse.core.commands.ParameterizedCommand.executeWithChecks(ParameterizedCommand.java:508)
        at org.eclipse.ui.internal.handlers.HandlerService.executeCommand(HandlerService.java:169)
        at org.eclipse.ui.internal.handlers.SlaveHandlerService.executeCommand(SlaveHandlerService.java:241)
        at org.eclipse.ui.internal.actions.CommandAction.runWithEvent(CommandAction.java:157)
        at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection(ActionContributionItem.java:584)
        at org.eclipse.jface.action.ActionContributionItem.access$2(ActionContributionItem.java:501)
        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:1258)
        at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3588)
        at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3209)
        at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2701)
        at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2665)
        at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2499)
        at org.eclipse.ui.internal.Workbench$7.run(Workbench.java:679)
        at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
        at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:668)
        at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
        at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:123)
        at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
        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:344)
        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:601)
        at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:622)
        at org.eclipse.equinox.launcher.Main.basicRun(Main.java:577)
        at org.eclipse.equinox.launcher.Main.run(Main.java:1410)
        at org.eclipse.equinox.launcher.Main.main(Main.java:1386)