java.lang.NullPointerException
        at java.lang.String.indexOf(String.java:1734)
        at java.lang.String.indexOf(String.java:1716)
        at org.netbeans.modules.refactoring.javascript.plugins.JsWhereUsedQueryPlugin$FindTask.searchTokenSequence(JsWhereUsedQueryPlugin.java:477)
        at org.netbeans.modules.refactoring.javascript.plugins.JsWhereUsedQueryPlugin$FindTask.run(JsWhereUsedQueryPlugin.java:397)
        at org.netbeans.modules.refactoring.javascript.plugins.JsWhereUsedQueryPlugin$FindTask.run(JsWhereUsedQueryPlugin.java:321)
        at org.netbeans.napi.gsfret.source.Source.runModificationTask(Source.java:628)
        at org.netbeans.modules.refactoring.javascript.plugins.JsRefactoringPlugin.processFiles(JsRefactoringPlugin.java:208)
        at org.netbeans.modules.refactoring.javascript.plugins.JsWhereUsedQueryPlugin.prepare(JsWhereUsedQueryPlugin.java:274)
        at org.netbeans.modules.refactoring.api.AbstractRefactoring.pluginsPrepare(AbstractRefactoring.java:380)
        at org.netbeans.modules.refactoring.api.AbstractRefactoring.prepare(AbstractRefactoring.java:202)
        at org.netbeans.modules.refactoring.spi.impl.ParametersPanel$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)