java.lang.AssertionError
   at org.openide.text.CloneableEditor$DoInitialize.initNonVisual(CloneableEditor.java:568)
   at org.openide.text.CloneableEditor$DoInitialize.run(CloneableEditor.java:324)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:641)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:1123)
Caused: org.openide.util.RequestProcessor$SlowItem: task failed due to: java.lang.AssertionError
   at org.openide.util.RequestProcessor$Task.schedule(RequestProcessor.java:694)
   at org.openide.text.CloneableEditor$DoInitialize.<init>(CloneableEditor.java:291)
   at org.openide.text.CloneableEditor.initialize(CloneableEditor.java:226)
   at org.openide.text.CloneableEditor.componentShowing(CloneableEditor.java:202)
   at org.openide.windows.WindowManager.componentShowing(WindowManager.java:332)
   at org.netbeans.core.windows.WindowManagerImpl.componentShowing(WindowManagerImpl.java:1022)
   at org.netbeans.core.windows.view.DefaultView.changeGUI(DefaultView.java:161)
   at org.netbeans.core.windows.ViewRequestor.dispatchRequest(ViewRequestor.java:269)
   at org.netbeans.core.windows.ViewRequestor.processRequest(ViewRequestor.java:245)
   at org.netbeans.core.windows.ViewRequestor.postRequest(ViewRequestor.java:183)
   at org.netbeans.core.windows.ViewRequestor.scheduleRequest(ViewRequestor.java:123)
   at org.netbeans.core.windows.Central.removeModeTopComponent(Central.java:990)
   at org.netbeans.core.windows.ModeImpl.removeTopComponent(ModeImpl.java:414)
   at org.netbeans.core.windows.ModeImpl.close(ModeImpl.java:243)
   at org.netbeans.core.windows.WindowManagerImpl.topComponentClose(WindowManagerImpl.java:1133)
   at org.openide.windows.TopComponent.close(TopComponent.java:552)
   at org.openide.windows.TopComponent.close(TopComponent.java:539)
   at org.netbeans.core.windows.actions.ActionUtils.closeAllDocuments(ActionUtils.java:274)
   at org.netbeans.core.windows.actions.CloseAllDocumentsAction.actionPerformed(CloseAllDocumentsAction.java:89)
   at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
   at javax.swing.AbstractButton$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:1223)
   at javax.swing.plaf.basic.BasicMenuItemUI$Handler.menuDragMouseReleased(BasicMenuItemUI.java:1327)
   at javax.swing.JMenuItem.fireMenuDragMouseReleased(JMenuItem.java:568)
   at javax.swing.JMenuItem.processMenuDragMouseEvent(JMenuItem.java:465)
   at javax.swing.JMenuItem.processMouseEvent(JMenuItem.java:411)
   at javax.swing.MenuSelectionManager.processMouseEvent(MenuSelectionManager.java:305)
   at javax.swing.plaf.basic.BasicPopupMenuUI$MouseGrabber.eventDispatched(BasicPopupMenuUI.java:807)
   at java.awt.Toolkit$SelectiveAWTEventListener.eventDispatched(Toolkit.java:2353)
   at java.awt.Toolkit$ToolkitEventMulticaster.eventDispatched(Toolkit.java:2245)
   at java.awt.Toolkit.notifyAWTEventListeners(Toolkit.java:2203)
   at java.awt.Component.dispatchEventImpl(Component.java:4528)
   at java.awt.Container.dispatchEventImpl(Container.java:2099)
   at java.awt.Component.dispatchEvent(Component.java:4460)
   at java.awt.LightweightDispatcher.retargetMouseEvent(LightweightDispatcher.java:4574)
   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:130)
   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)