java.lang.AssertionError
   at org.netbeans.modules.xml.xdm.XDMModel.<init>(XDMModel.java:103)
   at org.netbeans.modules.xml.xdm.xam.XDMAccess.<init>(XDMAccess.java:88)
   at org.netbeans.modules.xml.xdm.xam.XDMAccessProvider.createModelAccess(XDMAccessProvider.java:72)
   at org.netbeans.modules.xml.xam.dom.AbstractDocumentModel.getAccess(AbstractDocumentModel.java:570)
   at org.netbeans.modules.xml.xam.dom.AbstractDocumentModel.getAccess(AbstractDocumentModel.java:79)
   at org.netbeans.modules.xml.xam.AbstractModel.isAutoSyncActive(AbstractModel.java:704)
Caused: org.openide.util.RequestProcessor$SlowItem: task failed due to: java.lang.AssertionError
   at org.openide.util.RequestProcessor$Task.schedule(RequestProcessor.java:1456)
   at org.netbeans.modules.xml.xam.AbstractModelFactory$1.run(AbstractModelFactory.java:170)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1418)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:1957)