java.lang.NullPointerException
   at org.netbeans.modules.editor.lib2.view.DocumentView.updateStartEndOffsets(DocumentView.java:657)
   at org.netbeans.modules.editor.lib2.view.DocumentView.setParent(DocumentView.java:622)
   at javax.swing.plaf.basic.BasicTextUI$RootView.setView(BasicTextUI.java:1328)
   at javax.swing.plaf.basic.BasicTextUI.setView(BasicTextUI.java:693)
   at org.netbeans.editor.BaseTextUI.modelChanged(BaseTextUI.java:179)
   at javax.swing.plaf.basic.BasicTextUI$UpdateHandler.propertyChange(BasicTextUI.java:1786)
   at java.beans.PropertyChangeSupport.fire(PropertyChangeSupport.java:335)
   at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:327)
   at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:263)
   at java.awt.Component.firePropertyChange(Component.java:8382)
   at javax.swing.text.JTextComponent.setDocument(JTextComponent.java:453)
   at org.netbeans.modules.diff.builtin.visualizer.editable.EditableDiffView$TextualDiffRefreshTask$1.run(EditableDiffView.java:1196)
   at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
   at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:701)
   at java.awt.EventQueue.access$000(EventQueue.java:102)
   at java.awt.EventQueue$3.run(EventQueue.java:662)
   at java.awt.EventQueue$3.run(EventQueue.java:660)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:671)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:158)
   at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:244)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:163)
   at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:147)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:139)
   at java.awt.EventDispatchThread.run(EventDispatchThread.java:97)