javax.swing.text.BadLocationException: Modification not allowed
   at org.openide.text.CloneableEditorSupport$DocFilter.modificationNotAllowed(CloneableEditorSupport.java:2394)
   at org.openide.text.CloneableEditorSupport$DocFilter.checkModificationAllowed(CloneableEditorSupport.java:2388)
   at org.openide.text.CloneableEditorSupport$DocFilter.insertString(CloneableEditorSupport.java:2324)
   at org.netbeans.editor.BaseDocument.insertString(BaseDocument.java:755)
   at org.netbeans.editor.BaseKit$3.run(BaseKit.java:3371)
   at org.netbeans.editor.GuardedDocument.runAtomic(GuardedDocument.java:321)
   at org.netbeans.editor.BaseKit.changeRowIndent(BaseKit.java:3329)
   at org.netbeans.editor.BaseKit$InsertTabAction$1.run(BaseKit.java:1586)
   at org.netbeans.editor.GuardedDocument.runAtomicAsUser(GuardedDocument.java:351)
   at org.netbeans.editor.BaseKit$InsertTabAction.actionPerformed(BaseKit.java:1542)
   at org.netbeans.editor.BaseAction.actionPerformed(BaseAction.java:339)
   at javax.swing.SwingUtilities.notifyAction(SwingUtilities.java:1664)
   at javax.swing.JComponent.processKeyBinding(JComponent.java:2878)
   at javax.swing.JComponent.processKeyBindings(JComponent.java:2925)
   at javax.swing.JComponent.processKeyEvent(JComponent.java:2841)
   at java.awt.Component.processEvent(Component.java:6282)
   at java.awt.Container.processEvent(Container.java:2229)
   at java.awt.Component.dispatchEventImpl(Component.java:4861)
   at java.awt.Container.dispatchEventImpl(Container.java:2287)
   at java.awt.Component.dispatchEvent(Component.java:4687)
   at java.awt.KeyboardFocusManager.redispatchEvent(KeyboardFocusManager.java:1895)
   at java.awt.DefaultKeyboardFocusManager.dispatchKeyEvent(DefaultKeyboardFocusManager.java:762)
   at java.awt.DefaultKeyboardFocusManager.preDispatchKeyEvent(DefaultKeyboardFocusManager.java:1027)
   at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(DefaultKeyboardFocusManager.java:899)
   at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:727)
   at java.awt.Component.dispatchEventImpl(Component.java:4731)
   at java.awt.Container.dispatchEventImpl(Container.java:2287)
   at java.awt.Window.dispatchEventImpl(Window.java:2719)
   at java.awt.Component.dispatchEvent(Component.java:4687)
   at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:735)
   at java.awt.EventQueue.access$200(EventQueue.java:103)
   at java.awt.EventQueue$3.run(EventQueue.java:694)
   at java.awt.EventQueue$3.run(EventQueue.java:692)
   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:708)
   at java.awt.EventQueue$4.run(EventQueue.java:706)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:705)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:159)
   at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
   at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
   at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)