java.util.ConcurrentModificationException
   at java.util.HashMap$HashIterator.nextNode(HashMap.java:1429)
   at java.util.HashMap$EntryIterator.next(HashMap.java:1463)
   at java.util.HashMap$EntryIterator.next(HashMap.java:1461)
   at java.util.HashMap.putMapEntries(HashMap.java:511)
   at java.util.HashMap.<init>(HashMap.java:489)
   at org.netbeans.modules.html.editor.lib.api.SyntaxAnalyzerResult.getDeclaredNamespaces(SyntaxAnalyzerResult.java:587)
   at org.netbeans.modules.html.editor.api.gsf.HtmlParserResult.getNamespaces(HtmlParserResult.java:199)
   at org.netbeans.modules.html.editor.api.gsf.HtmlParserResult.roots(HtmlParserResult.java:181)
   at org.netbeans.modules.html.editor.api.gsf.HtmlParserResult.getAllRoots(HtmlParserResult.java:205)
   at org.netbeans.modules.html.editor.api.gsf.HtmlParserResult.findBySemanticRange(HtmlParserResult.java:214)
   at org.netbeans.modules.html.editor.HtmlElementProperties.runInEDT(HtmlElementProperties.java:164)
   at org.netbeans.modules.html.editor.HtmlElementProperties.access$000(HtmlElementProperties.java:96)
   at org.netbeans.modules.html.editor.HtmlElementProperties$1.run(HtmlElementProperties.java:137)
   at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
   at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756)
   at java.awt.EventQueue.access$500(EventQueue.java:97)
   at java.awt.EventQueue$3.run(EventQueue.java:709)
   at java.awt.EventQueue$3.run(EventQueue.java:703)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:726)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:159)
   at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
   at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
   at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)