java.lang.NullPointerException
   at com.sun.tools.mjavac.code.Types$DefaultTypeVisitor.visit(Types.java:3183)
   at com.sun.tools.mjavac.code.Types.hasSameArgs(Types.java:1894)
   at com.sun.tools.mjavac.code.Types.isSubSignature(Types.java:1863)
   at com.sun.tools.mjavac.code.Symbol$MethodSymbol.overrides(Symbol.java:1123)
   at com.sun.tools.mjavac.model.JavacElements.overrides(JavacElements.java:536)
   at org.netbeans.modules.javafx.editor.hints.MarkOverriddenTaskFactory$1.run(MarkOverriddenTaskFactory.java:118)
   at org.netbeans.modules.javafx.editor.hints.MarkOverriddenTaskFactory$1.run(MarkOverriddenTaskFactory.java:84)
   at org.netbeans.modules.javafx.source.parsing.JavaFXSourceCancelableTask.run(JavaFXSourceCancelableTask.java:104)
   at org.netbeans.modules.javafx.source.parsing.JavaFXSourceCancelableTask.run(JavaFXSourceCancelableTask.java:58)
   at org.netbeans.modules.parsing.impl.TaskProcessor$CompilationJob.run(TaskProcessor.java:664)
   at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
   at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
   at java.util.concurrent.FutureTask.run(FutureTask.java:138)
   at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
   at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
   at java.lang.Thread.run(Thread.java:637)