java.lang.AssertionError
        at org.netbeans.api.javafx.source.ElementHandle.create(ElementHandle.java:308)
        at org.netbeans.modules.javafx.refactoring.impl.scanners.BaseRefactoringScanner.<init>(BaseRefactoringScanner.java:61)
        at org.netbeans.modules.javafx.refactoring.impl.scanners.RenameScanner.<init>(RenameScanner.java:75)
        at org.netbeans.modules.javafx.refactoring.impl.plugins.RenameRefactoringPlugin$4.run(RenameRefactoringPlugin.java:387)
        at org.netbeans.modules.javafx.refactoring.impl.plugins.RenameRefactoringPlugin$4.run(RenameRefactoringPlugin.java:384)
        at org.netbeans.modules.javafx.source.parsing.LegacyUserTask.run(LegacyUserTask.java:68)
        at org.netbeans.modules.parsing.api.ParserManager$UserTaskAction.run(ParserManager.java:129)
        at org.netbeans.modules.parsing.api.ParserManager$UserTaskAction.run(ParserManager.java:113)
        at org.netbeans.modules.parsing.impl.TaskProcessor.runUserTask(TaskProcessor.java:190)
        at org.netbeans.modules.parsing.api.ParserManager.parse(ParserManager.java:99)
        at org.netbeans.api.javafx.source.JavaFXSource.runUserActionTask(JavaFXSource.java:247)
        at org.netbeans.modules.javafx.refactoring.impl.plugins.RenameRefactoringPlugin.prepare(RenameRefactoringPlugin.java:384)
        at org.netbeans.modules.refactoring.api.AbstractRefactoring.pluginsPrepare2(AbstractRefactoring.java:419)
        at org.netbeans.modules.refactoring.api.AbstractRefactoring.pluginsPrepare(AbstractRefactoring.java:403)
        at org.netbeans.modules.refactoring.api.AbstractRefactoring.prepare(AbstractRefactoring.java:214)
        at org.netbeans.modules.refactoring.spi.impl.ParametersPanel$Prepare.run(ParametersPanel.java:803)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:602)
        at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:1084)