java.lang.AssertionError
   at org.netbeans.modules.css.lib.api.CssParserResult.<init>(CssParserResult.java:68)
   at org.netbeans.modules.css.lib.nbparser.CssParser.getResult(CssParser.java:153)
   at org.netbeans.modules.css.lib.nbparser.CssParser.getResult(CssParser.java:73)
   at org.netbeans.modules.parsing.impl.TaskProcessor.callGetResult(TaskProcessor.java:615)
   at org.netbeans.modules.parsing.api.ParserManager$MimeTaskAction.run(ParserManager.java:380)
   at org.netbeans.modules.parsing.api.ParserManager$MimeTaskAction.run(ParserManager.java:365)
   at org.netbeans.modules.parsing.impl.TaskProcessor$2.call(TaskProcessor.java:206)
   at org.netbeans.modules.parsing.impl.TaskProcessor$2.call(TaskProcessor.java:203)
   at org.netbeans.modules.masterfs.filebasedfs.utils.FileChangedManager.priorityIO(FileChangedManager.java:176)
   at org.netbeans.modules.masterfs.providers.ProvidedExtensions.priorityIO(ProvidedExtensions.java:360)
   at org.netbeans.modules.parsing.impl.Utilities.runPriorityIO(Utilities.java:74)
   at org.netbeans.modules.parsing.impl.TaskProcessor.runUserTask(TaskProcessor.java:203)
   at org.netbeans.modules.parsing.api.ParserManager.parse(ParserManager.java:336)
   at org.netbeans.modules.css.visual.DocumentNode$DocumentChildren.refreshKeys(DocumentNode.java:142)
   at org.netbeans.modules.css.visual.DocumentNode$DocumentChildren.setModel(DocumentNode.java:130)
   at org.netbeans.modules.css.visual.DocumentNode$DocumentChildren.access$100(DocumentNode.java:104)
   at org.netbeans.modules.css.visual.DocumentNode.setModel(DocumentNode.java:91)
   at org.netbeans.modules.css.visual.DocumentViewPanel$6.run(DocumentViewPanel.java:349)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1432)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2042)
Caused: org.openide.util.RequestProcessor$SlowItem: task failed due to: java.lang.AssertionError
   at org.openide.util.RequestProcessor.post(RequestProcessor.java:424)
   at org.netbeans.modules.css.visual.DocumentViewPanel.contextChanged(DocumentViewPanel.java:346)
   at org.netbeans.modules.css.visual.DocumentViewPanel.access$200(DocumentViewPanel.java:99)
   at org.netbeans.modules.css.visual.DocumentViewPanel$2.resultChanged(DocumentViewPanel.java:164)
   at org.openide.util.lookup.ProxyLookup$1Notify.run(ProxyLookup.java:181)
   at org.openide.util.lookup.ProxyLookup.setLookups(ProxyLookup.java:190)
   at org.openide.util.lookup.ProxyLookup.setLookups(ProxyLookup.java:126)
   at org.netbeans.modules.css.visual.CssStylesPanel$ModifiableLookup.updateLookup(CssStylesPanel.java:356)
   at org.netbeans.modules.css.visual.CssStylesPanel.setContext(CssStylesPanel.java:287)
   at org.netbeans.modules.css.visual.api.CssStylesTC.setContext(CssStylesTC.java:124)
   at org.netbeans.modules.css.visual.CssStylesTCController$1$1.run(CssStylesTCController.java:134)
   at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
   at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:721)
   at java.awt.EventQueue.access$200(EventQueue.java:103)
   at java.awt.EventQueue$3.run(EventQueue.java:682)
   at java.awt.EventQueue$3.run(EventQueue.java:680)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:691)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:159)
   at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
   at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
   at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)