Unable to create this part due to an internal error. Reason for the failure: Editor could not be initialized.

I am getting this error message when I am trying to save the hibernate.cfg file.

Following is the stacktrace..

java.lang.NullPointerException
at org.eclipse.wst.sse.core.internal.FileBufferModelManager.getModel(FileBufferModelManager.java:440)
at org.eclipse.wst.sse.core.ModelManagerImpl._getModelFor(ModelManagerImpl.java:400)
at org.eclipse.wst.sse.core.ModelManagerImpl.getModelForEdit(ModelManagerImpl.java:1163)
at org.eclipse.wst.sse.ui.StructuredTextEditor.doSetInput(StructuredTextEditor.java:1294)
at org.eclipse.ui.texteditor.AbstractTextEditor$16.run(AbstractTextEditor.java:2360)
at org.eclipse.jface.operation.ModalContext.runInCurrentThread(ModalContext.java:346)
at org.eclipse.jface.operation.ModalContext.run(ModalContext.java:291)
at org.eclipse.jface.window.ApplicationWindow$1.run(ApplicationWindow.java:624)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:69)
at org.eclipse.jface.window.ApplicationWindow.run(ApplicationWindow.java:621)
at org.eclipse.ui.internal.WorkbenchWindow.run(WorkbenchWindow.java:2134)
at org.eclipse.ui.texteditor.AbstractTextEditor.internalInit(AbstractTextEditor.java:2378)
at org.eclipse.ui.texteditor.AbstractTextEditor.init(AbstractTextEditor.java:2405)
at org.eclipse.wst.sse.ui.StructuredTextEditor.init(StructuredTextEditor.java:1924)
at org.eclipse.ui.internal.EditorManager.createSite(EditorManager.java:773)
at org.eclipse.ui.internal.EditorReference.createPartHelper(EditorReference.java:572)
at org.eclipse.ui.internal.EditorReference.createPart(EditorReference.java:365)
at org.eclipse.ui.internal.WorkbenchPartReference.getPart(WorkbenchPartReference.java:552)
at org.eclipse.ui.internal.PartPane.setVisible(PartPane.java:283)
at org.eclipse.ui.internal.presentations.PresentablePart.setVisible(PresentablePart.java:126)
at org.eclipse.ui.internal.presentations.util.PresentablePartFolder.select(PresentablePartFolder.java:268)
at org.eclipse.ui.internal.presentations.util.LeftToRightTabOrder.select(LeftToRightTabOrder.java:65)
at org.eclipse.ui.internal.presentations.util.TabbedStackPresentation.selectPart(TabbedStackPresentation.java:391)
at org.eclipse.ui.internal.PartStack.refreshPresentationSelection(PartStack.java:1102)
at org.eclipse.ui.internal.PartStack.setSelection(PartStack.java:1051)
at org.eclipse.ui.internal.PartStack.showPart(PartStack.java:1256)
at org.eclipse.ui.internal.PartStack.add(PartStack.java:442)
at org.eclipse.ui.internal.EditorStack.add(EditorStack.java:109)
at org.eclipse.ui.internal.EditorSashContainer.addEditor(EditorSashContainer.java:60)
at org.eclipse.ui.internal.EditorAreaHelper.addToLayout(EditorAreaHelper.java:212)
at org.eclipse.ui.internal.EditorAreaHelper.addEditor(EditorAreaHelper.java:202)
at org.eclipse.ui.internal.EditorManager.createEditorTab(EditorManager.java:753)
at org.eclipse.ui.internal.EditorManager.openEditorFromDescriptor(EditorManager.java:665)
at org.eclipse.ui.internal.EditorManager.openEditor(EditorManager.java:628)
at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditorBatched(WorkbenchPage.java:2323)
at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditor(WorkbenchPage.java:2258)
at org.eclipse.ui.internal.WorkbenchPage.access$9(WorkbenchPage.java:2250)
at org.eclipse.ui.internal.WorkbenchPage$9.run(WorkbenchPage.java:2236)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:69)
at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2231)
at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2212)
at org.eclipse.ui.ide.IDE.openEditor(IDE.java:371)
at org.eclipse.ui.ide.IDE.openEditor(IDE.java:334)
at org.eclipse.jdt.internal.ui.javaeditor.EditorUtility.openInEditor(EditorUtility.java:137)
at org.eclipse.jdt.internal.ui.javaeditor.EditorUtility.openInEditor(EditorUtility.java:110)
at org.eclipse.jdt.internal.ui.actions.OpenActionUtil.open(OpenActionUtil.java:49)
at org.eclipse.jdt.ui.actions.OpenAction.run(OpenAction.java:164)
at org.eclipse.jdt.ui.actions.OpenAction.run(OpenAction.java:150)
at org.eclipse.jdt.ui.actions.SelectionDispatchAction.dispatchRun(SelectionDispatchAction.java:212)
at org.eclipse.jdt.ui.actions.SelectionDispatchAction.run(SelectionDispatchAction.java:188)
at org.eclipse.jdt.internal.ui.packageview.PackageExplorerActionGroup.handleOpen(PackageExplorerActionGroup.java:289)
at org.eclipse.jdt.internal.ui.packageview.PackageExplorerPart$4.open(PackageExplorerPart.java:490)
at org.eclipse.jface.viewers.StructuredViewer$2.run(StructuredViewer.java:741)
at org.eclipse.core.internal.runtime.InternalPlatform.run(InternalPlatform.java:1044)
at org.eclipse.core.runtime.Platform.run(Platform.java:783)
at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:44)
at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:148)
at org.eclipse.jface.viewers.StructuredViewer.fireOpen(StructuredViewer.java:739)
at org.eclipse.jface.viewers.StructuredViewer.handleOpen(StructuredViewer.java:968)
at org.eclipse.jface.viewers.StructuredViewer$6.handleOpen(StructuredViewer.java:1067)
at org.eclipse.jface.util.OpenStrategy.fireOpenEvent(OpenStrategy.java:243)
at org.eclipse.jface.util.OpenStrategy.access$2(OpenStrategy.java:238)
at org.eclipse.jface.util.OpenStrategy$1.handleEvent(OpenStrategy.java:277)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:66)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:843)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3080)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:2713)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:1699)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:1663)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:367)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:143)
at org.eclipse.ui.internal.ide.IDEApplication.run(IDEApplication.java:103)
at org.eclipse.core.internal.runtime.PlatformActivator$1.run(PlatformActivator.java:226)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:376)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:163)
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:324)
at org.eclipse.core.launcher.Main.invokeFramework(Main.java:334)
at org.eclipse.core.launcher.Main.basicRun(Main.java:278)
at org.eclipse.core.launcher.Main.run(Main.java:973)
at org.eclipse.core.launcher.Main.main(Main.java:948)

version info would be nice