java.lang.ClassCastException: org.netbeans.modules.css.gsf.api.CssParserResult cannot be cast to org.netbeans.modules.html.editor.gsf.HtmlParserResult
        at org.netbeans.modules.html.editor.gsf.HtmlStructureScanner.scan(HtmlStructureScanner.java:88)
        at org.netbeans.modules.csl.navigation.ElementScanningTask$1.run(ElementScanningTask.java:121)
        at org.netbeans.modules.csl.navigation.ElementScanningTask$1.run(ElementScanningTask.java:135)
        at org.netbeans.modules.parsing.api.ParserManager$UserTaskAction.run(ParserManager.java:129)
        at org.netbeans.modules.parsing.api.ParserManager$UserTaskAction.run(ParserManager.java:113)
Caused: org.netbeans.modules.parsing.spi.ParseException
        at org.netbeans.modules.parsing.impl.TaskProcessor.runUserTask(TaskProcessor.java:190)
        at org.netbeans.modules.parsing.api.ParserManager.parse(ParserManager.java:99)
        at org.netbeans.modules.csl.navigation.ElementScanningTask.run(ElementScanningTask.java:112)
        at org.netbeans.modules.csl.navigation.ClassMemberNavigatorSourceFactory$ProxyElementScanningTask.run(ClassMemberNavigatorSourceFactory.java:141)
        at org.netbeans.modules.csl.navigation.ClassMemberNavigatorSourceFactory$ProxyElementScanningTask.run(ClassMemberNavigatorSourceFactory.java:119)
        at org.netbeans.modules.parsing.impl.TaskProcessor$CompilationJob.run(TaskProcessor.java:681)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:0)
        at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:0)
        at java.util.concurrent.FutureTask.run(FutureTask.java:0)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:0)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:0)
        at java.lang.Thread.run(Thread.java:0)