title: Eclipse CDT - Could not open Editor: Editor could not be initialized?
body: <p>I'm running Eclipse Helios (3.6) with the latest CDT (plus HgEclipse, ANTLR IDE, PDT, and probably a few other things). It was running great, until recently in which when I tried to open any file that uses the C/C++ editor in CDT gives an error:</p>
  
  <pre><code>Could not open the editor: Editor could not be initialized.
  </code></pre>
  
  <p>The details option gives this:</p>
  
  <pre><code>java.lang.NullPointerException
      at java.util.TreeMap.getEntry(TreeMap.java:341)
      at java.util.TreeMap.get(TreeMap.java:272)
      at org.eclipse.cdt.internal.core.language.LanguageMappingStore.decodeFileMappings(LanguageMappingStore.java:124)
      at org.eclipse.cdt.internal.core.language.LanguageMappingStore.decodeMappings(LanguageMappingStore.java:85)
      at org.eclipse.cdt.core.model.LanguageManager.getLanguageConfiguration(LanguageManager.java:447)
      at org.eclipse.cdt.internal.core.language.LanguageMappingResolver.computeLanguage(LanguageMappingResolver.java:57)
      at org.eclipse.cdt.core.model.LanguageManager.getLanguageForFile(LanguageManager.java:587)
      at org.eclipse.cdt.internal.core.model.TranslationUnit.getLanguage(TranslationUnit.java:726)
      at org.eclipse.cdt.internal.ui.editor.CEditor.internalDoSetInput(CEditor.java:1405)
      at org.eclipse.cdt.internal.ui.editor.CEditor.doSetInput(CEditor.java:1358)
      at org.eclipse.ui.texteditor.AbstractTextEditor$19.run(AbstractTextEditor.java:3043)
      at org.eclipse.jface.operation.ModalContext.runInCurrentThread(ModalContext.java:464)
      at org.eclipse.jface.operation.ModalContext.run(ModalContext.java:372)
      at org.eclipse.jface.window.ApplicationWindow$1.run(ApplicationWindow.java:759)
      at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
      at org.eclipse.jface.window.ApplicationWindow.run(ApplicationWindow.java:756)
      at org.eclipse.ui.internal.WorkbenchWindow.run(WorkbenchWindow.java:2606)
      at org.eclipse.ui.texteditor.AbstractTextEditor.internalInit(AbstractTextEditor.java:3061)
      at org.eclipse.ui.texteditor.AbstractTextEditor.init(AbstractTextEditor.java:3088)
      at org.eclipse.ui.internal.EditorManager.createSite(EditorManager.java:798)
      at org.eclipse.ui.internal.EditorReference.createPartHelper(EditorReference.java:647)
      at org.eclipse.ui.internal.EditorReference.createPart(EditorReference.java:465)
      at org.eclipse.ui.internal.WorkbenchPartReference.getPart(WorkbenchPartReference.java:595)
      at org.eclipse.ui.internal.PartPane.setVisible(PartPane.java:313)
      at org.eclipse.ui.internal.presentations.PresentablePart.setVisible(PresentablePart.java:180)
      at org.eclipse.ui.internal.presentations.util.PresentablePartFolder.select(PresentablePartFolder.java:270)
      at org.eclipse.ui.internal.presentations.util.LeftToRightTabOrder.select(LeftToRightTabOrder.java:65)
      at org.eclipse.ui.internal.presentations.util.TabbedStackPresentation.selectPart(TabbedStackPresentation.java:473)
      at org.eclipse.ui.internal.PartStack.refreshPresentationSelection(PartStack.java:1254)
      at org.eclipse.ui.internal.PartStack.setSelection(PartStack.java:1207)
      at org.eclipse.ui.internal.PartStack.showPart(PartStack.java:1606)
      at org.eclipse.ui.internal.PartStack.add(PartStack.java:497)
      at org.eclipse.ui.internal.EditorStack.add(EditorStack.java:103)
      at org.eclipse.ui.internal.PartStack.add(PartStack.java:483)
      at org.eclipse.ui.internal.EditorStack.add(EditorStack.java:112)
      at org.eclipse.ui.internal.EditorSashContainer.addEditor(EditorSashContainer.java:63)
      at org.eclipse.ui.internal.EditorAreaHelper.addToLayout(EditorAreaHelper.java:225)
      at org.eclipse.ui.internal.EditorAreaHelper.addEditor(EditorAreaHelper.java:213)
      at org.eclipse.ui.internal.EditorManager.createEditorTab(EditorManager.java:778)
      at org.eclipse.ui.internal.EditorManager.openEditorFromDescriptor(EditorManager.java:677)
      at org.eclipse.ui.internal.EditorManager.openEditor(EditorManager.java:638)
      at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditorBatched(WorkbenchPage.java:2860)
      at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditor(WorkbenchPage.java:2768)
      at org.eclipse.ui.internal.WorkbenchPage.access$11(WorkbenchPage.java:2760)
      at org.eclipse.ui.internal.WorkbenchPage$10.run(WorkbenchPage.java:2711)
      at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
      at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2707)
      at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2691)
      at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2682)
      at org.eclipse.cdt.internal.ui.util.EditorUtility.openInEditor(EditorUtility.java:254)
      at org.eclipse.cdt.internal.ui.util.EditorUtility.openInEditor(EditorUtility.java:157)
      at org.eclipse.cdt.internal.ui.util.EditorUtility.openInEditor(EditorUtility.java:141)
      at org.eclipse.cdt.internal.ui.navigator.OpenCElementAction.run(OpenCElementAction.java:52)
      at org.eclipse.ui.actions.RetargetAction.run(RetargetAction.java:221)
      at org.eclipse.ui.navigator.CommonNavigatorManager$3.open(CommonNavigatorManager.java:185)
      at org.eclipse.ui.OpenAndLinkWithEditorHelper$InternalListener.open(OpenAndLinkWithEditorHelper.java:48)
      at org.eclipse.jface.viewers.StructuredViewer$2.run(StructuredViewer.java:845)
      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.viewers.StructuredViewer.fireOpen(StructuredViewer.java:843)
      at org.eclipse.jface.viewers.StructuredViewer.handleOpen(StructuredViewer.java:1131)
      at org.eclipse.ui.navigator.CommonViewer.handleOpen(CommonViewer.java:462)
      at org.eclipse.jface.viewers.StructuredViewer$6.handleOpen(StructuredViewer.java:1235)
      at org.eclipse.jface.util.OpenStrategy.fireOpenEvent(OpenStrategy.java:264)
      at org.eclipse.jface.util.OpenStrategy.access$2(OpenStrategy.java:258)
      at org.eclipse.jface.util.OpenStrategy$1.handleEvent(OpenStrategy.java:298)
      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:3540)
      at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3161)
      at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2640)
      at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2604)
      at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2438)
      at org.eclipse.ui.internal.Workbench$7.run(Workbench.java:671)
      at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
      at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:664)
      at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
      at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:115)
      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:369)
      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:616)
      at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:620)
      at org.eclipse.equinox.launcher.Main.basicRun(Main.java:575)
      at org.eclipse.equinox.launcher.Main.run(Main.java:1408)
  </code></pre>
  
  <p>I am using Eclipse x86 on Ubuntu 10.10 (also x86).</p>
  
  <p>If you think it might be the files themselves, you can access them at <a href="http://hg.redxdev.com/dyst" rel="nofollow">http://hg.redxdev.com/dyst</a> (username: anon password: anon).</p>
  
  <p>Thanks a lot!</p>