java.lang.NullPointerException
   at org.netbeans.api.java.source.SourceUtils.getDependentRootsImpl(SourceUtils.java:728)
   at org.netbeans.api.java.source.SourceUtils.getDependentRoots(SourceUtils.java:717)
   at org.netbeans.modules.refactoring.java.RetoucheUtils.getClasspathInfoFor(RetoucheUtils.java:614)
   at org.netbeans.modules.refactoring.java.RetoucheUtils.getClasspathInfoFor(RetoucheUtils.java:595)
   at org.netbeans.modules.refactoring.java.RetoucheUtils.getClasspathInfoFor(RetoucheUtils.java:591)
   at org.netbeans.modules.refactoring.java.ui.SafeDeleteUI.<init>(SafeDeleteUI.java:93)
   at org.netbeans.modules.refactoring.java.ui.RefactoringActionsProvider$10.createRefactoringUI(RefactoringActionsProvider.java:444)
   at org.netbeans.modules.refactoring.java.ui.RefactoringActionsProvider$NodeToFileObjectTask.run(RefactoringActionsProvider.java:869)
   at org.netbeans.modules.refactoring.java.RetoucheUtils.invokeAfterScanFinished(RetoucheUtils.java:952)
   at org.netbeans.modules.refactoring.java.ui.RefactoringActionsProvider.doDelete(RefactoringActionsProvider.java:450)
   at org.netbeans.modules.refactoring.api.impl.ActionsImplementationFactory.doDelete(ActionsImplementationFactory.java:132)
   at org.netbeans.modules.refactoring.spi.impl.SafeDeleteAction.performAction(SafeDeleteAction.java:79)
   at org.netbeans.modules.refactoring.spi.impl.RefactoringGlobalAction.performAction(RefactoringGlobalAction.java:132)
   at org.netbeans.modules.refactoring.spi.impl.SafeDeleteAction$1.run(SafeDeleteAction.java:126)
   at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:633)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:125)
   at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:296)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:211)
   at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:201)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:196)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:188)
   at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)