javax.swing.undo.CannotRedoException
   at javax.swing.undo.AbstractUndoableEdit.redo(AbstractUndoableEdit.java:142)
   at org.openide.text.WrapUndoEdit.redo(WrapUndoEdit.java:118)
   at org.openide.awt.UndoRedo$Manager.undoTo(UndoRedo.java:238)
   at org.openide.awt.UndoRedo$Manager.undo(UndoRedo.java:200)
   at org.openide.text.UndoRedoManager.access$301(UndoRedoManager.java:98)
   at org.openide.text.UndoRedoManager$DocLockedRun.run(UndoRedoManager.java:658)
   at org.netbeans.editor.GuardedDocument.runAtomic(GuardedDocument.java:323)
   at org.openide.text.UndoRedoManager$DocLockedRun.<init>(UndoRedoManager.java:631)
   at org.openide.text.UndoRedoManager$DocLockedRun.<init>(UndoRedoManager.java:623)
   at org.openide.text.UndoRedoManager$DocLockedRun.<init>(UndoRedoManager.java:619)
   at org.openide.text.UndoRedoManager.undo(UndoRedoManager.java:437)
   at org.netbeans.core.multiview.MultiViewPeer$DelegateUndoRedo.undo(MultiViewPeer.java:1106)
   at org.openide.actions.UndoAction.performAction(UndoAction.java:186)
   at org.openide.util.actions.CallableSystemAction$1.run(CallableSystemAction.java:130)
   at org.openide.util.actions.ActionInvoker$1.run(ActionInvoker.java:95)
   at org.openide.util.actions.ActionInvoker.doPerformAction(ActionInvoker.java:116)
   at org.openide.util.actions.ActionInvoker.invokeAction(ActionInvoker.java:99)
   at org.openide.util.actions.CallableSystemAction.actionPerformed(CallableSystemAction.java:127)
   at org.netbeans.modules.editor.NbEditorKit$NbUndoAction.actionPerformed(NbEditorKit.java:903)
   at org.netbeans.editor.BaseAction.actionPerformed(BaseAction.java:339)
   at javax.swing.SwingUtilities.notifyAction(SwingUtilities.java:1663)
   at javax.swing.JComponent.processKeyBinding(JComponent.java:2882)
   at javax.swing.JComponent.processKeyBindings(JComponent.java:2929)
   at javax.swing.JComponent.processKeyEvent(JComponent.java:2845)
   at java.awt.Component.processEvent(Component.java:6310)
   at java.awt.Container.processEvent(Container.java:2236)
   at java.awt.Component.dispatchEventImpl(Component.java:4889)
   at java.awt.Container.dispatchEventImpl(Container.java:2294)
   at java.awt.Component.dispatchEvent(Component.java:4711)
   at java.awt.KeyboardFocusManager.redispatchEvent(KeyboardFocusManager.java:1954)
   at java.awt.DefaultKeyboardFocusManager.dispatchKeyEvent(DefaultKeyboardFocusManager.java:806)
   at java.awt.DefaultKeyboardFocusManager.preDispatchKeyEvent(DefaultKeyboardFocusManager.java:1074)
   at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(DefaultKeyboardFocusManager.java:945)
   at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:771)
   at java.awt.Component.dispatchEventImpl(Component.java:4760)
   at java.awt.Container.dispatchEventImpl(Container.java:2294)
   at java.awt.Window.dispatchEventImpl(Window.java:2746)
   at java.awt.Component.dispatchEvent(Component.java:4711)
   at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
   at java.awt.EventQueue.access$500(EventQueue.java:97)
   at java.awt.EventQueue$3.run(EventQueue.java:709)
   at java.awt.EventQueue$3.run(EventQueue.java:703)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
   at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:90)
   at java.awt.EventQueue$4.run(EventQueue.java:731)
   at java.awt.EventQueue$4.run(EventQueue.java:729)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:159)
   at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
   at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
   at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)