edit some rather big page with VPE, input some test, during page refresh close VPE - as result get exception:

java.lang.NullPointerException
at org.jboss.tools.vpe.editor.mozilla.MozillaEditor.getDomDocument(MozillaEditor.java:828)
at org.jboss.tools.vpe.editor.VpeVisualDomBuilder.getVisualDocument(VpeVisualDomBuilder.java:1556)
at org.jboss.tools.vpe.editor.VpeVisualDomBuilder.createNode(VpeVisualDomBuilder.java:493)
at org.jboss.tools.vpe.editor.VpeVisualDomBuilder.addNode(VpeVisualDomBuilder.java:270)
at org.jboss.tools.vpe.editor.VpeVisualDomBuilder.updateElement(VpeVisualDomBuilder.java:836)
at org.jboss.tools.vpe.editor.VpeVisualDomBuilder.updateNode(VpeVisualDomBuilder.java:766)
at org.jboss.tools.vpe.editor.VpeController.notifyChangedInUiThread(VpeController.java:748)
at org.jboss.tools.vpe.editor.VpeController$1.runInUIThread(VpeController.java:554)
at org.eclipse.ui.progress.UIJob$1.run(UIJob.java:95)
at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:35)
at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:135)
at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:4140)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3757)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2696)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2660)
at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2494)
at org.eclipse.ui.internal.Workbench$7.run(Workbench.java:674)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:667)
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:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
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)