java.lang.NullPointerException
        at org.netbeans.modules.refactoring.java.RetoucheUtils.getOverridingMethods(RetoucheUtils.java:210)
        at org.netbeans.modules.refactoring.java.plugins.RenameRefactoringPlugin.preCheck(RenameRefactoringPlugin.java:159)
        at org.netbeans.modules.refactoring.java.spi.JavaRefactoringPlugin$WorkingTask.run(JavaRefactoringPlugin.java:294)
        at org.netbeans.modules.refactoring.java.spi.JavaRefactoringPlugin$WorkingTask.run(JavaRefactoringPlugin.java:271)
        at org.netbeans.api.java.source.JavaSource.runUserActionTask(JavaSource.java:602)
        at org.netbeans.modules.refactoring.java.spi.JavaRefactoringPlugin$WorkingTask.run(JavaRefactoringPlugin.java:284)
        at org.netbeans.modules.refactoring.java.spi.JavaRefactoringPlugin$WorkingTask.access$100(JavaRefactoringPlugin.java:271)
        at org.netbeans.modules.refactoring.java.spi.JavaRefactoringPlugin.preCheck(JavaRefactoringPlugin.java:104)
        at org.netbeans.modules.refactoring.api.AbstractRefactoring.pluginsPreCheck(AbstractRefactoring.java:334)
        at org.netbeans.modules.refactoring.api.AbstractRefactoring.preCheck(AbstractRefactoring.java:182)
        at org.netbeans.modules.refactoring.spi.impl.ParametersPanel$10.run(ParametersPanel.java:467)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:561)
        at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:986)