java.lang.Throwable
   at org.netbeans.modules.editor.fold.FoldChildren.insertImpl(FoldChildren.java:247)
   at org.netbeans.modules.editor.fold.FoldChildren.insertImpl(FoldChildren.java:227)
   at org.netbeans.modules.editor.fold.FoldChildren.replaceByChildren(FoldChildren.java:215)
   at org.netbeans.api.editor.fold.Fold.replaceByChildren(Fold.java:377)
   at org.netbeans.api.editor.fold.FoldHierarchy$ApiPackageAccessorImpl.foldReplaceByChildren(FoldHierarchy.java:398)
   at org.netbeans.modules.editor.fold.FoldHierarchyTransactionImpl.removeFoldFromHierarchy(FoldHierarchyTransactionImpl.java:1004)
   at org.netbeans.modules.editor.fold.FoldHierarchyTransactionImpl.removeFold(FoldHierarchyTransactionImpl.java:476)
   at org.netbeans.modules.editor.fold.FoldHierarchyExecution.remove(FoldHierarchyExecution.java:498)
   at org.netbeans.modules.editor.fold.FoldOperationImpl.removeFromHierarchy(FoldOperationImpl.java:206)
   at org.netbeans.modules.editor.fold.FoldOperationImpl$Refresher.run(FoldOperationImpl.java:670)
   at org.netbeans.modules.editor.fold.FoldOperationImpl.update(FoldOperationImpl.java:489)
   at org.netbeans.spi.editor.fold.FoldOperation.update(FoldOperation.java:406)
   at org.netbeans.modules.csl.editor.fold.GsfFoldManager$CommitFolds.run(GsfFoldManager.java:679)
   at org.netbeans.editor.BaseDocument.render(BaseDocument.java:1391)
   at org.netbeans.modules.csl.editor.fold.GsfFoldManager$CommitFolds.run(GsfFoldManager.java:662)
   at org.netbeans.modules.csl.editor.fold.GsfFoldManager$JavaElementFoldTask.run(GsfFoldManager.java:384)
   at org.netbeans.modules.csl.editor.fold.GsfFoldManager$JavaElementFoldTask.run(GsfFoldManager.java:268)
   at org.netbeans.modules.parsing.impl.TaskProcessor.callParserResultTask(TaskProcessor.java:568)
   at org.netbeans.modules.parsing.impl.TaskProcessor$CompilationJob.run(TaskProcessor.java:744)
   at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
   at java.util.concurrent.FutureTask.run(FutureTask.java:262)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1432)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2042)