java.lang.NullPointerException
   at com.sun.tools.javac.main.JavaCompiler.resolveIdent(JavaCompiler.java:765)
   at com.sun.tools.javac.main.JavaCompiler.resolveIdent(JavaCompiler.java:740)
   at com.sun.tools.javac.model.JavacElements.binaryNameToClassSymbol(JavacElements.java:132)
   at com.sun.tools.javac.model.JavacElements.getTypeElementByBinaryName(JavacElements.java:123)
   at org.netbeans.api.java.source.ElementHandle.getTypeElementByBinaryName(ElementHandle.java:623)
   at org.netbeans.api.java.source.ElementHandle.resolveImpl(ElementHandle.java:161)
   at org.netbeans.api.java.source.ElementHandle.resolve(ElementHandle.java:137)
   at org.netbeans.api.java.source.TreePathHandle$TreeDelegate.resolveElement(TreePathHandle.java:555)
   at org.netbeans.api.java.source.TreePathHandle.resolveElement(TreePathHandle.java:187)
   at org.netbeans.modules.j2ee.jpa.refactoring.whereused.PersistenceXmlWhereUsed$1.run(PersistenceXmlWhereUsed.java:107)
   at org.netbeans.modules.j2ee.jpa.refactoring.whereused.PersistenceXmlWhereUsed$1.run(PersistenceXmlWhereUsed.java:99)
   at org.netbeans.api.java.source.JavaSource$MultiTask.run(JavaSource.java:486)
   at org.netbeans.modules.parsing.impl.TaskProcessor.callUserTask(TaskProcessor.java:609)
   at org.netbeans.modules.parsing.api.ParserManager$UserTaskAction.run(ParserManager.java:153)
   at org.netbeans.modules.parsing.api.ParserManager$UserTaskAction.run(ParserManager.java:137)
   at org.netbeans.modules.parsing.impl.TaskProcessor$2.call(TaskProcessor.java:204)
   at org.netbeans.modules.parsing.impl.TaskProcessor$2.call(TaskProcessor.java:201)
   at org.netbeans.modules.masterfs.filebasedfs.utils.FileChangedManager.priorityIO(FileChangedManager.java:176)
   at org.netbeans.modules.masterfs.providers.ProvidedExtensions.priorityIO(ProvidedExtensions.java:360)
   at org.netbeans.modules.parsing.nb.DataObjectEnvFactory.runPriorityIO(DataObjectEnvFactory.java:141)
   at org.netbeans.modules.parsing.impl.Utilities.runPriorityIO(Utilities.java:88)
   at org.netbeans.modules.parsing.impl.TaskProcessor.runUserTask(TaskProcessor.java:201)
   at org.netbeans.modules.parsing.api.ParserManager.parse(ParserManager.java:104)
   at org.netbeans.api.java.source.JavaSource.runUserActionTaskImpl(JavaSource.java:436)
   at org.netbeans.api.java.source.JavaSource.runUserActionTask(JavaSource.java:407)
   at org.netbeans.modules.j2ee.jpa.refactoring.whereused.PersistenceXmlWhereUsed.prepare(PersistenceXmlWhereUsed.java:99)
   at org.netbeans.modules.refactoring.api.AbstractRefactoring.pluginsPrepare2(AbstractRefactoring.java:442)
   at org.netbeans.modules.refactoring.api.AbstractRefactoring.pluginsPrepare(AbstractRefactoring.java:426)
   at org.netbeans.modules.refactoring.api.AbstractRefactoring.prepare(AbstractRefactoring.java:237)
   at org.netbeans.modules.refactoring.spi.impl.ParametersPanel$Prepare$2.run(ParametersPanel.java:1055)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1443)
   at org.netbeans.modules.openide.util.GlobalLookup.execute(GlobalLookup.java:68)
   at org.openide.util.lookup.Lookups.executeWith(Lookups.java:303)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2058)