java.lang.IllegalStateException: Annotation not added: null
   at org.netbeans.modules.editor.NbEditorDocument.removeAnnotation(NbEditorDocument.java:252)
   at org.openide.text.NbDocument.removeAnnotation(NbDocument.java:519)
   at org.openide.text.DocumentLine.attachDetachAnnotations(DocumentLine.java:418)
   at org.openide.text.DocumentLine$LR.run(DocumentLine.java:904)
   at org.openide.text.DocumentLine$LR.invoke(DocumentLine.java:920)
   at org.openide.text.DocumentLine$LR.stateChanged(DocumentLine.java:925)
   at org.openide.util.WeakListenerImpl$Change.stateChanged(WeakListenerImpl.java:329)
   at org.openide.text.CloneableEditorSupport.fireStateChangeEvent(CloneableEditorSupport.java:2370)
   at org.openide.text.CloneableEditorSupport.fireDocumentChange(CloneableEditorSupport.java:2353)
   at org.openide.text.CloneableEditorSupport.closeDocument(CloneableEditorSupport.java:2231)
   at org.openide.text.CloneableEditorSupport.notifyClosed(CloneableEditorSupport.java:2096)
   at org.openide.text.DataEditorSupport.notifyClosed(DataEditorSupport.java:374)
   at org.openide.text.CloneableEditor.closeLast(CloneableEditor.java:886)
   at org.openide.windows.CloneableTopComponent$Ref.unregister(CloneableTopComponent.java:406)
   at org.openide.windows.CloneableTopComponent$Ref.access$300(CloneableTopComponent.java:270)
   at org.openide.windows.CloneableTopComponent.canClose(CloneableTopComponent.java:209)
   at org.openide.text.CloneableEditor.canClose(CloneableEditor.java:199)
   at org.netbeans.core.windows.Central.removeModeTopComponent(Central.java:953)
   at org.netbeans.core.windows.Central.userClosedTopComponent(Central.java:1989)
   at org.netbeans.core.windows.view.DefaultView.userClosedTopComponent(DefaultView.java:746)
   at org.netbeans.core.windows.view.ui.TabbedHandler.actionPerformed(TabbedHandler.java:324)
   at org.netbeans.swing.tabcontrol.TabbedContainer.postActionEvent(TabbedContainer.java:695)
   at org.netbeans.swing.tabcontrol.TabbedContainerUI.shouldPerformAction(TabbedContainerUI.java:165)
   at org.netbeans.swing.tabcontrol.plaf.DefaultTabbedContainerUI.access$2700(DefaultTabbedContainerUI.java:112)
   at org.netbeans.swing.tabcontrol.plaf.DefaultTabbedContainerUI$DisplayerActionListener.actionPerformed(DefaultTabbedContainerUI.java:1269)
   at org.netbeans.swing.tabcontrol.TabDisplayer.postActionEvent(TabDisplayer.java:580)
   at org.netbeans.swing.tabcontrol.TabDisplayerUI.shouldPerformAction(TabDisplayerUI.java:188)
   at org.netbeans.swing.tabcontrol.plaf.BasicTabDisplayerUI.access$1500(BasicTabDisplayerUI.java:120)
   at org.netbeans.swing.tabcontrol.plaf.BasicTabDisplayerUI$BasicDisplayerMouseListener.performCommand(BasicTabDisplayerUI.java:731)
   at org.netbeans.swing.tabcontrol.plaf.BasicTabDisplayerUI$BasicDisplayerMouseListener.potentialCommand(BasicTabDisplayerUI.java:716)
   at org.netbeans.swing.tabcontrol.plaf.BasicTabDisplayerUI$BasicDisplayerMouseListener.mouseReleased(BasicTabDisplayerUI.java:764)
   at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:289)
   at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:289)
   at java.awt.Component.processMouseEvent(Component.java:6504)
   at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
   at java.awt.Component.processEvent(Component.java:6269)
   at java.awt.Container.processEvent(Container.java:2229)
   at java.awt.Component.dispatchEventImpl(Component.java:4860)
   at java.awt.Container.dispatchEventImpl(Container.java:2287)
   at java.awt.Component.dispatchEvent(Component.java:4686)
   at java.awt.LightweightDispatcher.retargetMouseEvent(LightweightDispatcher.java:4832)
   at java.awt.LightweightDispatcher.processMouseEvent(LightweightDispatcher.java:4492)
   at java.awt.LightweightDispatcher.dispatchEvent(LightweightDispatcher.java:4422)
   at java.awt.Container.dispatchEventImpl(Container.java:2273)
   at java.awt.Window.dispatchEventImpl(Window.java:2713)
   at java.awt.Component.dispatchEvent(Component.java:4686)
   at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:707)
   at java.awt.EventQueue.access$000(EventQueue.java:101)
   at java.awt.EventQueue$3.run(EventQueue.java:666)
   at java.awt.EventQueue$3.run(EventQueue.java:664)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
   at java.awt.EventQueue$4.run(EventQueue.java:680)
   at java.awt.EventQueue$4.run(EventQueue.java:678)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:677)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:148)
   at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:211)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:128)
   at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:117)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:113)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:105)
   at java.awt.EventDispatchThread.run(EventDispatchThread.java:90)