java.lang.NullPointerException
        at org.netbeans.modules.editor.NbEditorDocument.createEditor(NbEditorDocument.java:170)
        at org.openide.text.CloneableEditor$DoInitialize.initCustomEditor(CloneableEditor.java:497)
        at org.openide.text.CloneableEditor$DoInitialize.initVisual(CloneableEditor.java:599)
        at org.openide.text.CloneableEditor.getEditorPane(CloneableEditor.java:1067)
        at org.openide.text.CloneableEditorSupport.getOpenedPanes(CloneableEditorSupport.java:1098)
        at org.netbeans.modules.cnd.qnavigator.navigator.NavigatorModel.findCurrentJEditorPane(NavigatorModel.java:261)
        at org.netbeans.modules.cnd.qnavigator.navigator.NavigatorModel.checkCursor(NavigatorModel.java:233)
        at org.netbeans.modules.cnd.qnavigator.navigator.NavigatorModel.access$200(NavigatorModel.java:78)
        at org.netbeans.modules.cnd.qnavigator.navigator.NavigatorModel$3.actionPerformed(NavigatorModel.java:126)
        at javax.swing.Timer.fireActionPerformed(Timer.java:271)
        at javax.swing.Timer$DoPostEvent.run(Timer.java:201)
        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:117)
        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)