java.lang.NullPointerException
   at com.sun.tools.mjavac.code.Symbol$MethodSymbol.params(Symbol.java:1201)
   at com.sun.tools.mjavac.code.Symbol$MethodSymbol.getParameters(Symbol.java:1233)
   at com.sun.tools.mjavac.code.Symbol$MethodSymbol.getParameters(Symbol.java:985)
   at org.netbeans.modules.javafx.editor.completion.JavaFXCompletionItem$MethodItem.<init>(JavaFXCompletionItem.java:733)
   at org.netbeans.modules.javafx.editor.completion.JavaFXCompletionItem$MethodItem.<init>(JavaFXCompletionItem.java:692)
   at org.netbeans.modules.javafx.editor.completion.JavaFXCompletionItem.createExecutableItem(JavaFXCompletionItem.java:132)
   at org.netbeans.modules.javafx.editor.completion.JavaFXCompletionEnvironment.addMembers(JavaFXCompletionEnvironment.java:400)
   at org.netbeans.modules.javafx.editor.completion.environment.MemberSelectTreeEnvironment.inside(MemberSelectTreeEnvironment.java:144)
   at org.netbeans.modules.javafx.editor.completion.environment.MemberSelectTreeEnvironment.inside(MemberSelectTreeEnvironment.java:67)
   at org.netbeans.modules.javafx.editor.completion.JavaFXCompletionQuery.resolveCompletion(JavaFXCompletionQuery.java:397)
   at org.netbeans.modules.javafx.editor.completion.JavaFXCompletionQuery.run(JavaFXCompletionQuery.java:344)
   at org.netbeans.modules.javafx.editor.completion.JavaFXCompletionQuery.run(JavaFXCompletionQuery.java:77)
   at org.netbeans.modules.javafx.source.parsing.LegacyUserTask.run(LegacyUserTask.java:68)
   at org.netbeans.modules.parsing.api.ParserManager$UserTaskAction.run(ParserManager.java:129)
   at org.netbeans.modules.parsing.api.ParserManager$UserTaskAction.run(ParserManager.java:113)
Caused: org.netbeans.modules.parsing.spi.ParseException
   at org.netbeans.modules.parsing.impl.TaskProcessor.runUserTask(TaskProcessor.java:192)
   at org.netbeans.modules.parsing.impl.TaskProcessor.runWhenScanFinished(TaskProcessor.java:221)
   at org.netbeans.modules.parsing.api.ParserManager.parseWhenScanFinished(ParserManager.java:106)
Caused: java.io.IOException
   at org.netbeans.api.javafx.source.JavaFXSource.runWhenScanFinished(JavaFXSource.java:279)
   at org.netbeans.modules.javafx.editor.completion.JavaFXCompletionQuery.query(JavaFXCompletionQuery.java:241)
   at org.netbeans.spi.editor.completion.support.AsyncCompletionTask.run(AsyncCompletionTask.java:218)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:641)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:1123)