java.lang.NullPointerException
   at org.netbeans.modules.refactoring.java.plugins.RenameRefactoringPlugin.checkParameters(RenameRefactoringPlugin.java:396)
   at org.netbeans.modules.refactoring.java.spi.JavaRefactoringPlugin$WorkingTask.run(JavaRefactoringPlugin.java:356)
   at org.netbeans.modules.refactoring.java.spi.JavaRefactoringPlugin$WorkingTask.run(JavaRefactoringPlugin.java:329)
   at org.netbeans.api.java.source.JavaSource$MultiTask.run(JavaSource.java:493)
   at org.netbeans.modules.parsing.impl.TaskProcessor.callUserTask(TaskProcessor.java:593)
   at org.netbeans.modules.parsing.api.ParserManager$UserTaskAction.run(ParserManager.java:155)
   at org.netbeans.modules.parsing.api.ParserManager$UserTaskAction.run(ParserManager.java:139)
   at org.netbeans.modules.parsing.impl.TaskProcessor$2.call(TaskProcessor.java:206)
   at org.netbeans.modules.parsing.impl.TaskProcessor$2.call(TaskProcessor.java:203)
   at org.netbeans.modules.masterfs.filebasedfs.utils.FileChangedManager.priorityIO(FileChangedManager.java:176)
   at org.netbeans.modules.masterfs.providers.ProvidedExtensions.priorityIO(ProvidedExtensions.java:360)
   at org.netbeans.modules.parsing.impl.Utilities.runPriorityIO(Utilities.java:74)
   at org.netbeans.modules.parsing.impl.TaskProcessor.runUserTask(TaskProcessor.java:203)
   at org.netbeans.modules.parsing.api.ParserManager.parse(ParserManager.java:106)
   at org.netbeans.api.java.source.JavaSource.runUserActionTaskImpl(JavaSource.java:443)
   at org.netbeans.api.java.source.JavaSource.runUserActionTask(JavaSource.java:414)
   at org.netbeans.modules.refactoring.java.spi.JavaRefactoringPlugin$WorkingTask.run(JavaRefactoringPlugin.java:342)
   at org.netbeans.modules.refactoring.java.spi.JavaRefactoringPlugin$WorkingTask.access$100(JavaRefactoringPlugin.java:329)
   at org.netbeans.modules.refactoring.java.spi.JavaRefactoringPlugin.checkParameters(JavaRefactoringPlugin.java:141)
   at org.netbeans.modules.refactoring.api.AbstractRefactoring.pluginsCheckParams(AbstractRefactoring.java:505)
   at org.netbeans.modules.refactoring.api.AbstractRefactoring.checkParameters(AbstractRefactoring.java:264)
   at org.netbeans.modules.refactoring.java.ui.RenameRefactoringUI.setParameters(RenameRefactoringUI.java:246)
   at org.netbeans.modules.refactoring.spi.impl.ParametersPanel$Prepare.run(ParametersPanel.java:991)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1432)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2042)