java.lang.IllegalArgumentException: Comparison method violates its general contract!
   at java.util.TimSort.mergeHi(TimSort.java:899)
   at java.util.TimSort.mergeAt(TimSort.java:516)
   at java.util.TimSort.mergeCollapse(TimSort.java:441)
   at java.util.TimSort.sort(TimSort.java:245)
   at java.util.Arrays.sort(Arrays.java:1512)
   at org.netbeans.modules.editor.structure.api.DocumentModel$ElementsArray.resort(DocumentModel.java:1430)
   at org.netbeans.modules.editor.structure.api.DocumentModel.checkDocumentDirty(DocumentModel.java:560)
   at org.netbeans.modules.editor.structure.api.DocumentModel.getLeafElementForOffset(DocumentModel.java:354)
   at org.netbeans.modules.xml.text.structure.XMLDocumentModelProvider.updateModel(XMLDocumentModelProvider.java:108)
   at org.netbeans.modules.editor.structure.api.DocumentModel.updateModel(DocumentModel.java:512)
   at org.netbeans.modules.editor.structure.api.DocumentModel.access$000(DocumentModel.java:128)
   at org.netbeans.modules.editor.structure.api.DocumentModel$1.run(DocumentModel.java:191)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1443)
   at org.netbeans.modules.openide.util.GlobalLookup.execute(GlobalLookup.java:68)
   at org.openide.util.lookup.Lookups.executeWith(Lookups.java:303)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2058)