java.lang.AssertionError
        at org.netbeans.modules.java.source.JavaFileFilterQuery.getFilter(JavaFileFilterQuery.java:60)
        at org.netbeans.modules.java.source.parsing.JavacParser.<init>(JavacParser.java:223)
        at org.netbeans.modules.java.source.parsing.JavacParserFactory.createParser(JavacParserFactory.java:64)
        at org.netbeans.modules.java.source.parsing.JavacParserFactory.createParser(JavacParserFactory.java:56)
        at org.netbeans.modules.parsing.impl.SourceCache.getParser(SourceCache.java:154)
        at org.netbeans.modules.parsing.impl.SourceCache.getResult(SourceCache.java:167)
        at org.netbeans.modules.parsing.api.ResultIterator.getParserResult(ResultIterator.java:115)
        at org.netbeans.modules.languages.features.MarkOccurrencesSupport$1$1.run(MarkOccurrencesSupport.java:99)
        at org.netbeans.modules.parsing.api.ParserManager$UserTaskAction.run(ParserManager.java:123)
        at org.netbeans.modules.parsing.api.ParserManager$UserTaskAction.run(ParserManager.java:105)
        at org.netbeans.modules.parsing.impl.TaskProcessor.runUserTask(TaskProcessor.java:191)
        at org.netbeans.modules.parsing.api.ParserManager.parse(ParserManager.java:96)
        at org.netbeans.modules.languages.features.MarkOccurrencesSupport$1.run(MarkOccurrencesSupport.java:96)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:573)
        at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:1005)