A structured model client, org.jboss.tools.jst.jsp.support.kb.WTPTextJspKbConnector$MyDocumentAdapter@13a037e threw following exception during adapter notification (CONTENT_CHANGED )

java.lang.NullPointerException
	at org.jboss.tools.jst.jsp.support.kb.WTPTextJspKbConnector.updateKnownTagLists(WTPTextJspKbConnector.java:271)
	at org.jboss.tools.jst.jsp.support.kb.WTPTextJspKbConnector.invokeDelayedUpdateKnownTagLists(WTPTextJspKbConnector.java:189)
	at org.jboss.tools.jst.jsp.support.kb.WTPTextJspKbConnector$MyDocumentAdapter.notifyChanged(WTPTextJspKbConnector.java:416)
	at org.eclipse.wst.sse.core.internal.provisional.AbstractNotifier.notify(AbstractNotifier.java:201)
	at org.eclipse.wst.xml.core.internal.document.XMLModelNotifierImpl.notify(XMLModelNotifierImpl.java:238)
	at org.eclipse.wst.xml.core.internal.document.XMLModelNotifierImpl.notifyDeferred(XMLModelNotifierImpl.java:340)
	at org.eclipse.wst.xml.core.internal.document.XMLModelNotifierImpl.endChanging(XMLModelNotifierImpl.java:178)
	at org.eclipse.wst.xml.core.internal.document.DOMModelImpl.changedModel(DOMModelImpl.java:163)
	at org.eclipse.wst.sse.core.internal.model.AbstractStructuredModel$DocumentToModelNotifier.regionChanged(AbstractStructuredModel.java:164)
	at org.eclipse.wst.sse.core.internal.text.BasicStructuredDocument._fireEvent(BasicStructuredDocument.java:544)
	at org.eclipse.wst.sse.core.internal.text.BasicStructuredDocument.fireStructuredDocumentEvent(BasicStructuredDocument.java:1183)
	at org.eclipse.wst.sse.core.internal.text.BasicStructuredDocument.internalReplaceText(BasicStructuredDocument.java:1955)
	at org.eclipse.wst.sse.core.internal.text.BasicStructuredDocument.replaceText(BasicStructuredDocument.java:2394)
	at org.eclipse.wst.sse.core.internal.text.JobSafeStructuredDocument.access$0(JobSafeStructuredDocument.java:1)
	at org.eclipse.wst.sse.core.internal.text.JobSafeStructuredDocument$1.run(JobSafeStructuredDocument.java:98)
	at org.eclipse.wst.sse.ui.EditorExecutionContext.execute(EditorExecutionContext.java:42)
	at org.eclipse.wst.sse.core.internal.text.JobSafeStructuredDocument.replaceText(JobSafeStructuredDocument.java:109)
	at org.eclipse.wst.sse.core.internal.text.BasicStructuredDocument.replaceText(BasicStructuredDocument.java:2390)
	at org.eclipse.wst.sse.ui.internal.StructuredDocumentToTextAdapter.replaceTextRange(StructuredDocumentToTextAdapter.java:1187)
	at org.eclipse.swt.custom.StyledText.modifyContent(StyledText.java:5757)
	at org.eclipse.swt.custom.StyledText.sendKeyEvent(StyledText.java:6500)
	at org.eclipse.swt.custom.StyledText.doBackspace(StyledText.java:2111)
	at org.eclipse.swt.custom.StyledText.invokeAction(StyledText.java:5645)
	at org.eclipse.swt.custom.StyledText.handleKey(StyledText.java:5033)
	at org.eclipse.swt.custom.StyledText.handleKeyDown(StyledText.java:5054)
	at org.eclipse.swt.custom.StyledText$7.handleEvent(StyledText.java:4800)
	at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:66)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:938)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:962)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:947)
	at org.eclipse.swt.widgets.Widget.sendKeyEvent(Widget.java:975)
	at org.eclipse.swt.widgets.Widget.sendKeyEvent(Widget.java:971)
	at org.eclipse.swt.widgets.Widget.wmChar(Widget.java:1285)
	at org.eclipse.swt.widgets.Control.WM_CHAR(Control.java:3772)
	at org.eclipse.swt.widgets.Control.windowProc(Control.java:3672)
	at org.eclipse.swt.widgets.Canvas.windowProc(Canvas.java:291)
	at org.eclipse.swt.widgets.Display.windowProc(Display.java:4351)
	at org.eclipse.swt.internal.win32.OS.DispatchMessageW(Native Method)
	at org.eclipse.swt.internal.win32.OS.DispatchMessage(OS.java:2265)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3291)
	at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2389)
	at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2353)
	at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2219)
	at org.eclipse.ui.internal.Workbench$4.run(Workbench.java:466)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:289)
	at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:461)
	at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
	at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:106)
	at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:169)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:106)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:76)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:363)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:176)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)
	at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:508)
	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:447)
	at org.eclipse.equinox.launcher.Main.run(Main.java:1173)