java.lang.IllegalStateException
   at org.netbeans.modules.properties.PropertiesStructure.getParent(PropertiesStructure.java:149)
   at org.netbeans.modules.properties.PropertiesStructure.getParentBundleStructure(PropertiesStructure.java:157)
   at org.netbeans.modules.properties.PropertiesFileEntry$PropKeysChildren.mySetKeys(PropertiesFileEntry.java:461)
   at org.netbeans.modules.properties.PropertiesFileEntry$PropKeysChildren.addNotify(PropertiesFileEntry.java:481)
   at org.openide.nodes.Children.callAddNotify(Children.java:575)
   at org.openide.nodes.EntrySupportDefault.getArray(EntrySupportDefault.java:650)
   at org.openide.nodes.EntrySupportDefault.getNodes(EntrySupportDefault.java:121)
   at org.openide.nodes.EntrySupportDefault.getNodes(EntrySupportDefault.java:172)
   at org.openide.nodes.Children.getNodes(Children.java:469)
   at org.openide.nodes.FilterNode$Children$DefaultSupport.updateKeys(FilterNode.java:1721)
   at org.openide.nodes.FilterNode$Children$DefaultSupport.update(FilterNode.java:1708)
   at org.openide.nodes.FilterNode$Children.addNotifyImpl(FilterNode.java:1499)
   at org.openide.nodes.FilterNode$Children.addNotify(FilterNode.java:1492)
   at org.openide.nodes.Children.callAddNotify(Children.java:575)
   at org.openide.nodes.EntrySupportDefault.getArray(EntrySupportDefault.java:650)
   at org.openide.nodes.EntrySupportDefault.getNodes(EntrySupportDefault.java:121)
   at org.openide.nodes.EntrySupportDefault.getNodes(EntrySupportDefault.java:172)
   at org.openide.nodes.Children.getNodes(Children.java:469)
   at org.openide.nodes.FilterNode$Children$DefaultSupport.updateKeys(FilterNode.java:1721)
   at org.openide.nodes.FilterNode$Children$DefaultSupport.update(FilterNode.java:1708)
   at org.openide.nodes.FilterNode$Children.addNotifyImpl(FilterNode.java:1499)
   at org.openide.nodes.FilterNode$Children.addNotify(FilterNode.java:1492)
   at org.openide.nodes.Children.callAddNotify(Children.java:575)
   at org.openide.nodes.EntrySupportDefault.getArray(EntrySupportDefault.java:650)
   at org.openide.nodes.EntrySupportDefault.getNodes(EntrySupportDefault.java:121)
   at org.openide.nodes.EntrySupportDefault.getNodes(EntrySupportDefault.java:172)
   at org.openide.nodes.EntrySupportDefault.getNodesCount(EntrySupportDefault.java:176)
   at org.openide.nodes.Children.getNodesCount(Children.java:509)
   at org.openide.nodes.Node$1.run(Node.java:530)
   at org.netbeans.modules.openide.util.DefaultMutexImplementation.postRequest(DefaultMutexImplementation.java:1039)
   at org.netbeans.modules.openide.util.DefaultMutexImplementation.postRequest(DefaultMutexImplementation.java:985)
   at org.netbeans.modules.openide.util.DefaultMutexImplementation.postWriteRequest(DefaultMutexImplementation.java:356)
   at org.openide.util.Mutex.postWriteRequest(Mutex.java:388)
   at org.openide.nodes.Node.setChildren(Node.java:504)
   at org.openide.nodes.FilterNode.changeOriginal(FilterNode.java:443)
   at org.openide.loaders.FolderChildren$DelayedNode.run(FolderChildren.java:561)
   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)