java.lang.NullPointerException
        at org.netbeans.modules.refactoring.java.RetoucheUtils.getOverridingMethods(RetoucheUtils.java:221)
        at org.netbeans.modules.refactoring.java.plugins.RenameRefactoringPlugin$2.run(RenameRefactoringPlugin.java:417)
        at org.netbeans.modules.refactoring.java.plugins.RenameRefactoringPlugin$2.run(RenameRefactoringPlugin.java:390)
        at org.netbeans.api.java.source.JavaSource.runUserActionTask(JavaSource.java:665)
        at org.netbeans.modules.refactoring.java.plugins.RenameRefactoringPlugin.getRelevantFiles(RenameRefactoringPlugin.java:384)
        at org.netbeans.modules.refactoring.java.plugins.RenameRefactoringPlugin.prepare(RenameRefactoringPlugin.java:449)
        at org.netbeans.modules.refactoring.api.AbstractRefactoring.pluginsPrepare(AbstractRefactoring.java:380)
        at org.netbeans.modules.refactoring.api.AbstractRefactoring.prepare(AbstractRefactoring.java:202)
        at org.netbeans.modules.refactoring.spi.impl.ParametersPanel$Prepare.run(ParametersPanel.java:765)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:561)
        at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:986)