java.lang.AssertionError
   at org.openide.text.CloneableEditor$DoInitialize.initNonVisual(CloneableEditor.java:592)
   at org.openide.text.CloneableEditor$DoInitialize.run(CloneableEditor.java:332)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1424)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:1968)
Caused: org.openide.util.RequestProcessor$SlowItem: task failed due to: java.lang.AssertionError
   at org.openide.util.RequestProcessor$Task.schedule(RequestProcessor.java:1465)
   at org.openide.text.CloneableEditor$DoInitialize.<init>(CloneableEditor.java:297)
   at org.openide.text.CloneableEditor.initialize(CloneableEditor.java:232)
   at org.openide.text.CloneableEditor.componentShowing(CloneableEditor.java:208)
   at org.openide.windows.WindowManager.componentShowing(WindowManager.java:339)
   at org.netbeans.core.windows.WindowManagerImpl.componentShowing(WindowManagerImpl.java:1025)
   at org.netbeans.core.windows.view.DefaultView.changeGUI(DefaultView.java:164)
   at org.netbeans.core.windows.ViewRequestor.dispatchRequest(ViewRequestor.java:272)
   at org.netbeans.core.windows.ViewRequestor.processRequest(ViewRequestor.java:248)
   at org.netbeans.core.windows.ViewRequestor.postRequest(ViewRequestor.java:186)
   at org.netbeans.core.windows.ViewRequestor.scheduleRequest(ViewRequestor.java:126)
   at org.netbeans.core.windows.Central.addModeClosedTopComponent(Central.java:856)
   at org.netbeans.core.windows.ModeImpl.addClosedTopComponent(ModeImpl.java:326)
   at org.netbeans.core.windows.ModeImpl.close(ModeImpl.java:244)
   at org.netbeans.core.windows.WindowManagerImpl.topComponentClose(WindowManagerImpl.java:1136)
   at org.openide.windows.TopComponent.close(TopComponent.java:567)
   at org.openide.windows.TopComponent.close(TopComponent.java:554)
   at org.netbeans.core.windows.actions.ActionUtils.closeAllDocuments(ActionUtils.java:277)
   at org.netbeans.core.windows.actions.CloseAllDocumentsAction.actionPerformed(CloseAllDocumentsAction.java:92)
   at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
   at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
   at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
   at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
   at javax.swing.AbstractButton.doClick(AbstractButton.java:357)
   at javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:809)
   at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(BasicMenuItemUI.java:850)
   at java.awt.Component.processMouseEvent(Component.java:6267)
   at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
   at java.awt.Component.processEvent(Component.java:6032)
   at java.awt.Container.processEvent(Container.java:2041)
   at java.awt.Component.dispatchEventImpl(Component.java:4630)
   at java.awt.Container.dispatchEventImpl(Container.java:2099)
   at java.awt.Component.dispatchEvent(Component.java:4460)
   at java.awt.LightweightDispatcher.retargetMouseEvent(LightweightDispatcher.java:4577)
   at java.awt.LightweightDispatcher.processMouseEvent(LightweightDispatcher.java:4238)
   at java.awt.LightweightDispatcher.dispatchEvent(LightweightDispatcher.java:4168)
   at java.awt.Container.dispatchEventImpl(Container.java:2085)
   at java.awt.Window.dispatchEventImpl(Window.java:2478)
   at java.awt.Component.dispatchEvent(Component.java:4460)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:148)
   at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
   at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
   at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)