java.lang.NullPointerException
	at org.openide.text.CloneableEditorSupport$Listener.run(CloneableEditorSupport.java:2749)
	at org.openide.text.CloneableEditorSupport$2.doRun(CloneableEditorSupport.java:636)
	at org.openide.text.CloneableEditorSupport$2.run(CloneableEditorSupport.java:607)
	at org.netbeans.editor.GuardedDocument.runAtomic(GuardedDocument.java:294)
	at org.openide.text.NbDocument.runAtomic(NbDocument.java:384)
	at org.openide.text.CloneableEditorSupport$2.doRun(CloneableEditorSupport.java:617)
	at org.openide.text.CloneableEditorSupport$2.run(CloneableEditorSupport.java:607)
	at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:572)
[catch] at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:997)