java.lang.NullPointerException
   at java.lang.String.compareTo(String.java:1167)
   at org.openide.explorer.view.OutlineView$OutlineViewOutline$OutlineViewOutlineColumn$NodeNestedComparator.compare(OutlineView.java:1228)
   at org.netbeans.swing.outline.Outline$OutlineColumn$OutlineRowComparator.compare(Outline.java:435)
   at org.netbeans.swing.outline.Outline$OutlineColumn$OutlineRowComparator.compare(Outline.java:365)
   at org.netbeans.swing.etable.ETableColumnModel$CompoundComparator.compare(ETableColumnModel.java:320)
   at org.netbeans.swing.etable.ETableColumnModel$CompoundComparator.compare(ETableColumnModel.java:308)
   at java.util.Arrays.mergeSort(Arrays.java:1270)
   at java.util.Arrays.mergeSort(Arrays.java:1282)
   at java.util.Arrays.mergeSort(Arrays.java:1281)
   at java.util.Arrays.sort(Arrays.java:1210)
   at java.util.Collections.sort(Collections.java:159)
   at org.netbeans.swing.etable.ETable.sortAndFilter(ETable.java:1446)
   at org.netbeans.swing.etable.ETable.convertRowIndexToModel(ETable.java:1196)
   at javax.swing.JTable.getValueAt(JTable.java:2686)
   at org.netbeans.swing.etable.ETable.getValueAt(ETable.java:641)
   at javax.swing.JTable.prepareRenderer(JTable.java:5703)
   at javax.swing.plaf.basic.BasicTableUI.paintCell(BasicTableUI.java:2072)
   at javax.swing.plaf.basic.BasicTableUI.paintCells(BasicTableUI.java:1974)
   at javax.swing.plaf.basic.BasicTableUI.paint(BasicTableUI.java:1770)
   at javax.swing.plaf.ComponentUI.update(ComponentUI.java:143)
   at javax.swing.JComponent.paintComponent(JComponent.java:752)
   at javax.swing.JComponent.paint(JComponent.java:1029)
   at javax.swing.JComponent.paintChildren(JComponent.java:862)
   at javax.swing.JComponent.paint(JComponent.java:1038)
   at javax.swing.JViewport.paint(JViewport.java:747)
   at javax.swing.JComponent.paintChildren(JComponent.java:862)
   at javax.swing.JComponent.paint(JComponent.java:1038)
   at javax.swing.JComponent.paintChildren(JComponent.java:862)
   at javax.swing.JComponent.paint(JComponent.java:1038)
   at javax.swing.JComponent.paintChildren(JComponent.java:862)
   at javax.swing.JComponent.paint(JComponent.java:1038)
   at javax.swing.JComponent.paintChildren(JComponent.java:862)
   at javax.swing.JComponent.paint(JComponent.java:1038)
   at javax.swing.JComponent.paintChildren(JComponent.java:862)
   at javax.swing.JComponent.paint(JComponent.java:1038)
   at javax.swing.JComponent.paintChildren(JComponent.java:862)
   at javax.swing.JComponent.paint(JComponent.java:1038)
   at org.netbeans.swing.tabcontrol.TabbedContainer.paint(TabbedContainer.java:956)
   at javax.swing.JComponent.paintChildren(JComponent.java:862)
   at javax.swing.JComponent.paint(JComponent.java:1038)
   at javax.swing.JComponent.paintChildren(JComponent.java:862)
   at javax.swing.JComponent.paint(JComponent.java:1038)
   at org.netbeans.core.windows.view.ui.MultiSplitPane.paint(MultiSplitPane.java:325)
   at javax.swing.JComponent.paintChildren(JComponent.java:862)
   at javax.swing.JComponent.paint(JComponent.java:1038)
   at org.netbeans.core.windows.view.ui.MultiSplitPane.paint(MultiSplitPane.java:325)
   at javax.swing.JComponent.paintChildren(JComponent.java:862)
   at javax.swing.JComponent.paint(JComponent.java:1038)
   at javax.swing.JComponent.paintChildren(JComponent.java:862)
   at javax.swing.JComponent.paint(JComponent.java:1038)
   at javax.swing.JLayeredPane.paint(JLayeredPane.java:567)
   at javax.swing.JComponent.paintChildren(JComponent.java:862)
   at javax.swing.JComponent.paint(JComponent.java:1038)
   at javax.swing.JComponent.paintChildren(JComponent.java:862)
   at javax.swing.JComponent.paint(JComponent.java:1038)
   at javax.swing.JComponent.paintChildren(JComponent.java:862)
   at javax.swing.JComponent.paint(JComponent.java:1038)
   at javax.swing.JLayeredPane.paint(JLayeredPane.java:567)
   at javax.swing.JComponent.paintChildren(JComponent.java:862)
   at javax.swing.JComponent.paintToOffscreen(JComponent.java:5131)
   at javax.swing.RepaintManager$PaintManager.paintDoubleBuffered(RepaintManager.java:1479)
   at javax.swing.RepaintManager$PaintManager.paint(RepaintManager.java:1410)
   at javax.swing.BufferStrategyPaintManager.paint(BufferStrategyPaintManager.java:294)
   at javax.swing.RepaintManager.paint(RepaintManager.java:1224)
   at javax.swing.JComponent.paint(JComponent.java:1015)
   at java.awt.GraphicsCallback$PaintCallback.run(GraphicsCallback.java:21)
   at sun.awt.SunGraphicsCallback.runOneComponent(SunGraphicsCallback.java:60)
   at sun.awt.SunGraphicsCallback.runComponents(SunGraphicsCallback.java:97)
   at java.awt.Container.paint(Container.java:1780)
   at java.awt.Window.paint(Window.java:3375)
   at org.netbeans.core.windows.view.ui.MainWindow.paint(MainWindow.java:553)
   at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:796)
   at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:713)
   at javax.swing.RepaintManager.seqPaintDirtyRegions(RepaintManager.java:693)
   at javax.swing.SystemEventQueueUtilities$ComponentWorkRequest.run(SystemEventQueueUtilities.java:125)
   at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:597)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:134)
   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)