1) Close all pages
2) DND attached page into workspace

ASSERT: Page should be opened with JBoss Editor w/o any exceptions.
RESULT:
java.lang.NullPointerException
at org.jboss.tools.jst.jsp.contentassist.JspContentAssistProcessor.getTagLibraries(JspContentAssistProcessor.java:147)
at org.jboss.tools.jst.jsp.contentassist.FaceletPageContectAssistProcessor.createContext(FaceletPageContectAssistProcessor.java:69)
at org.jboss.tools.jst.jsp.contentassist.JspContentAssistProcessor.createContext(JspContentAssistProcessor.java:1)
at org.jboss.tools.jst.jsp.contentassist.AbstractXMLContentAssistProcessor.createContext(AbstractXMLContentAssistProcessor.java:243)
at org.jboss.tools.jst.jsp.outline.JSPPropertySourceAdapter.setTarget(JSPPropertySourceAdapter.java:106)
at org.jboss.tools.jst.jsp.outline.JSPPropertySourceAdapter.<init>(JSPPropertySourceAdapter.java:84)
at org.jboss.tools.jst.jsp.outline.JSPPropertySheetConfiguration$JSPPropertySourceProvider0.getPropertySource(JSPPropertySheetConfiguration.java:56)
at org.eclipse.ui.views.properties.PropertySheetEntry.getPropertySource(PropertySheetEntry.java:470)
at org.eclipse.ui.views.properties.PropertySheetEntry.setValues(PropertySheetEntry.java:752)
at org.eclipse.ui.views.properties.PropertySheetViewer.setInput(PropertySheetViewer.java:973)
at org.eclipse.ui.views.properties.PropertySheetPage.selectionChanged(PropertySheetPage.java:510)
at org.eclipse.wst.sse.ui.internal.properties.ConfigurablePropertySheetPage.selectionChanged(ConfigurablePropertySheetPage.java:174)
at org.eclipse.ui.internal.AbstractSelectionService.firePostSelection(AbstractSelectionService.java:179)
at org.eclipse.ui.internal.AbstractSelectionService$2.selectionChanged(AbstractSelectionService.java:71)
at org.jboss.tools.jst.jsp.jspeditor.JSPMultiPageSelectionProvider$2.run(JSPMultiPageSelectionProvider.java:144)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
at org.jboss.tools.jst.jsp.jspeditor.JSPMultiPageSelectionProvider.fireSelectionChanged(JSPMultiPageSelectionProvider.java:142)
at org.jboss.tools.jst.jsp.jspeditor.JSPMultiPageSelectionProvider.firePostSelectionChanged(JSPMultiPageSelectionProvider.java:131)
at org.jboss.tools.jst.jsp.jspeditor.JSPMultiPageEditor$1.handlePostSelectionChanged(JSPMultiPageEditor.java:330)
at org.jboss.tools.jst.jsp.jspeditor.JSPMultiPageEditor$1$1.selectionChanged(JSPMultiPageEditor.java:313)
at org.eclipse.wst.sse.ui.StructuredTextEditor$5.run(StructuredTextEditor.java:627)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
at org.eclipse.wst.sse.ui.StructuredTextEditor$StructuredSelectionProvider.fireSelectionChanged(StructuredTextEditor.java:625)
at org.eclipse.wst.sse.ui.StructuredTextEditor$StructuredSelectionProvider.handlePostSelectionChanged(StructuredTextEditor.java:706)
at org.eclipse.wst.sse.ui.StructuredTextEditor$4.selectionChanged(StructuredTextEditor.java:599)
at org.eclipse.jface.text.TextViewer.firePostSelectionChanged(TextViewer.java:2731)
at org.eclipse.jface.text.TextViewer.firePostSelectionChanged(TextViewer.java:2679)
at org.eclipse.jface.text.TextViewer$5.run(TextViewer.java:2658)
at org.eclipse.swt.widgets.Display.runTimer(Display.java:3943)
at org.eclipse.swt.widgets.Display.messageProc(Display.java:3135)
at org.eclipse.swt.internal.win32.OS.DispatchMessageW(Native Method)
at org.eclipse.swt.internal.win32.OS.DispatchMessage(OS.java:2409)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3471)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2405)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2369)
at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2221)
at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:500)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:493)
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:194)
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:368)
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:585)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:559)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:514)
at org.eclipse.equinox.launcher.Main.run(Main.java:1311)
at org.eclipse.equinox.launcher.Main.main(Main.java:1287)