java.lang.RuntimeException
        at org.netbeans.modules.refactoring.java.plugins.JavaWhereUsedQueryPlugin.getRelevantFiles(JavaWhereUsedQueryPlugin.java:162)
        at org.netbeans.modules.refactoring.java.plugins.JavaWhereUsedQueryPlugin.prepare(JavaWhereUsedQueryPlugin.java:173)
        at org.netbeans.modules.refactoring.api.AbstractRefactoring.pluginsPrepare(AbstractRefactoring.java:329)
        at org.netbeans.modules.refactoring.api.AbstractRefactoring.prepare(AbstractRefactoring.java:176)
        at org.netbeans.modules.refactoring.spi.impl.ParametersPanel$Prepare.run(ParametersPanel.java:690)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:541)
[catch] at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:963)
Caused by: java.io.IOException
        at org.netbeans.api.java.source.JavaSource.runUserActionTask(JavaSource.java:428)
        at org.netbeans.modules.refactoring.java.plugins.JavaWhereUsedQueryPlugin.getRelevantFiles(JavaWhereUsedQueryPlugin.java:160)
        ... 6 more
Caused by: java.lang.IllegalArgumentException: Cannot pass null as an argument of the SourceUtils.getFile
        at org.netbeans.api.java.source.SourceUtils.getFile(SourceUtils.java:226)
        at org.netbeans.modules.refactoring.java.plugins.JavaWhereUsedQueryPlugin$1.run(JavaWhereUsedQueryPlugin.java:123)
        at org.netbeans.modules.refactoring.java.plugins.JavaWhereUsedQueryPlugin$1.run(JavaWhereUsedQueryPlugin.java:96)
        at org.netbeans.api.java.source.JavaSource.runUserActionTask(JavaSource.java:421)
        ... 7 more