java.lang.NullPointerException
   at org.netbeans.modules.java.editor.fold.ParsingFoldSupport$FM.invalidate(ParsingFoldSupport.java:489)
   at org.netbeans.modules.java.editor.fold.ParsingFoldSupport$FM.insertUpdate(ParsingFoldSupport.java:498)
   at org.netbeans.modules.editor.fold.FoldOperationImpl.insertUpdate(FoldOperationImpl.java:243)
   at org.netbeans.modules.editor.fold.FoldHierarchyExecution.insertUpdate(FoldHierarchyExecution.java:983)
   at org.netbeans.lib.editor.util.swing.PriorityDocumentListenerList.insertUpdate(PriorityDocumentListenerList.java:85)
   at javax.swing.text.AbstractDocument.fireInsertUpdate(AbstractDocument.java:202)
   at org.netbeans.editor.BaseDocument.fireInsertUpdate(BaseDocument.java:1624)
   at org.netbeans.editor.BaseDocument.handleInsertString(BaseDocument.java:829)
   at org.netbeans.editor.BaseDocument.insertString(BaseDocument.java:757)
   at org.netbeans.modules.java.editor.JavaEditorWarmUpTask.run(JavaEditorWarmUpTask.java:239)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1423)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2033)
Caused: org.openide.util.RequestProcessor$FastItem: task failed due to: java.lang.NullPointerException