java.lang.Exception: Owner stack
   at org.netbeans.modules.parsing.lucene.LuceneIndex$DirCache$IndexWriterReference.trace(LuceneIndex.java:1196)
   at org.netbeans.modules.parsing.lucene.LuceneIndex$DirCache$IndexWriterReference.acquire(LuceneIndex.java:1133)
   at org.netbeans.modules.parsing.lucene.LuceneIndex$DirCache.acquireWriter(LuceneIndex.java:899)
   at org.netbeans.modules.parsing.lucene.LuceneIndex.txStore(LuceneIndex.java:401)
   at org.netbeans.modules.java.source.usages.PersistentClassIndex$PIWriter.deleteAndFlush(PersistentClassIndex.java:503)
   at org.netbeans.modules.java.source.usages.SourceAnalyzerFactory$StorableAnalyzer.store(SourceAnalyzerFactory.java:225)
   at org.netbeans.modules.java.source.indexing.JavaParsingContext.store(JavaParsingContext.java:264)
   at org.netbeans.modules.java.source.indexing.JavaCustomIndexer.index(JavaCustomIndexer.java:324)
   at org.netbeans.modules.parsing.spi.indexing.Indexable$MyAccessor$2.run(Indexable.java:161)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater.runIndexer(RepositoryUpdater.java:296)
   at org.netbeans.modules.parsing.spi.indexing.Indexable$MyAccessor.index(Indexable.java:159)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.doIndex(RepositoryUpdater.java:2753)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.access$500(RepositoryUpdater.java:2157)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work$1.run(RepositoryUpdater.java:2639)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work$1.run(RepositoryUpdater.java:2637)
   at org.netbeans.modules.parsing.impl.indexing.errors.TaskCache.refreshTransaction(TaskCache.java:565)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.index(RepositoryUpdater.java:2637)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work$3.call(RepositoryUpdater.java:3290)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work$3.call(RepositoryUpdater.java:3256)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$4.run(RepositoryUpdater.java:2130)
   at org.openide.util.lookup.Lookups.executeWith(Lookups.java:304)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater.runInContext(RepositoryUpdater.java:2126)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater.runInContext(RepositoryUpdater.java:2107)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater.access$1200(RepositoryUpdater.java:157)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.scanFiles(RepositoryUpdater.java:3256)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$FileListWork.getDone(RepositoryUpdater.java:3775)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.doTheWork(RepositoryUpdater.java:3410)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task._run(RepositoryUpdater.java:6174)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task.access$4300(RepositoryUpdater.java:5825)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task$2$1.run(RepositoryUpdater.java:6090)
   at org.openide.util.lookup.Lookups.executeWith(Lookups.java:304)
   at org.netbeans.modules.parsing.impl.RunWhenScanFinishedSupport.performScan(RunWhenScanFinishedSupport.java:106)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task$2.call(RepositoryUpdater.java:6086)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task$2.call(RepositoryUpdater.java:6082)
   at org.netbeans.modules.masterfs.filebasedfs.utils.FileChangedManager.priorityIO(FileChangedManager.java:176)
   at org.netbeans.modules.masterfs.providers.ProvidedExtensions.priorityIO(ProvidedExtensions.java:360)
   at org.netbeans.modules.parsing.nb.DataObjectEnvFactory.runPriorityIO(DataObjectEnvFactory.java:141)
   at org.netbeans.modules.parsing.impl.Utilities.runPriorityIO(Utilities.java:88)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task.run(RepositoryUpdater.java:6082)
   at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
   at java.util.concurrent.FutureTask.run(FutureTask.java:266)
Caused: java.lang.IllegalStateException: Other thread using opened writer, old owner Thread Thread[RepositoryUpdater.worker,1,system](117), new owner Thread Thread[Code Completion,1,system](112).
   at org.netbeans.modules.parsing.lucene.LuceneIndex$DirCache$IndexWriterReference.assertSingleThreadWriter(LuceneIndex.java:1159)
   at org.netbeans.modules.parsing.lucene.LuceneIndex$DirCache$IndexWriterReference.acquire(LuceneIndex.java:1128)
   at org.netbeans.modules.parsing.lucene.LuceneIndex$DirCache.acquireWriter(LuceneIndex.java:899)
   at org.netbeans.modules.parsing.lucene.LuceneIndex.txStore(LuceneIndex.java:401)
   at org.netbeans.modules.java.source.usages.PersistentClassIndex$PIWriter.deleteAndFlush(PersistentClassIndex.java:503)
   at org.netbeans.modules.java.source.usages.SourceAnalyzerFactory$StorableAnalyzer.store(SourceAnalyzerFactory.java:225)
   at org.netbeans.modules.java.source.indexing.JavaParsingContext.store(JavaParsingContext.java:264)
   at org.netbeans.modules.java.source.indexing.JavaCustomIndexer.index(JavaCustomIndexer.java:324)
   at org.netbeans.modules.parsing.spi.indexing.Indexable$MyAccessor$2.run(Indexable.java:161)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater.runIndexer(RepositoryUpdater.java:296)
   at org.netbeans.modules.parsing.spi.indexing.Indexable$MyAccessor.index(Indexable.java:159)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.doIndex(RepositoryUpdater.java:2753)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.access$500(RepositoryUpdater.java:2157)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work$1.run(RepositoryUpdater.java:2639)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work$1.run(RepositoryUpdater.java:2637)
   at org.netbeans.modules.parsing.impl.indexing.errors.TaskCache.refreshTransaction(TaskCache.java:565)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.index(RepositoryUpdater.java:2637)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work$3.call(RepositoryUpdater.java:3290)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work$3.call(RepositoryUpdater.java:3256)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$4.run(RepositoryUpdater.java:2130)
   at org.openide.util.lookup.Lookups.executeWith(Lookups.java:304)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater.runInContext(RepositoryUpdater.java:2126)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater.runInContext(RepositoryUpdater.java:2107)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater.access$1200(RepositoryUpdater.java:157)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.scanFiles(RepositoryUpdater.java:3256)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$FileListWork.getDone(RepositoryUpdater.java:3775)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.doTheWork(RepositoryUpdater.java:3410)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$1T.run(RepositoryUpdater.java:424)
   at org.netbeans.modules.parsing.impl.indexing.SuspendSupport.runWithNoSuspend(SuspendSupport.java:130)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$1T.call(RepositoryUpdater.java:429)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$1T.call(RepositoryUpdater.java:421)
   at org.netbeans.modules.masterfs.filebasedfs.utils.FileChangedManager.priorityIO(FileChangedManager.java:176)
   at org.netbeans.modules.masterfs.providers.ProvidedExtensions.priorityIO(ProvidedExtensions.java:360)
   at org.netbeans.modules.parsing.nb.DataObjectEnvFactory.runPriorityIO(DataObjectEnvFactory.java:141)
   at org.netbeans.modules.parsing.impl.Utilities.runPriorityIO(Utilities.java:88)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater.enforcedFileListUpdate(RepositoryUpdater.java:435)
   at org.netbeans.modules.parsing.spi.indexing.support.QuerySupport$Query$1.call(QuerySupport.java:642)
   at org.netbeans.modules.parsing.spi.indexing.support.QuerySupport$Query$1.call(QuerySupport.java:613)
   at org.netbeans.modules.masterfs.filebasedfs.utils.FileChangedManager.priorityIO(FileChangedManager.java:176)
   at org.netbeans.modules.masterfs.providers.ProvidedExtensions.priorityIO(ProvidedExtensions.java:360)
   at org.netbeans.modules.parsing.nb.DataObjectEnvFactory.runPriorityIO(DataObjectEnvFactory.java:141)
   at org.netbeans.modules.parsing.impl.Utilities.runPriorityIO(Utilities.java:88)
   at org.netbeans.modules.parsing.spi.indexing.support.QuerySupport$Query.execute(QuerySupport.java:613)
   at org.netbeans.modules.parsing.spi.indexing.support.QuerySupport.query(QuerySupport.java:365)
   at org.netbeans.modules.groovy.editor.api.GroovyIndex.search(GroovyIndex.java:707)
   at org.netbeans.modules.groovy.editor.api.GroovyIndex.getClasses(GroovyIndex.java:174)
   at org.netbeans.modules.groovy.editor.api.GroovyIndex.getAllClasses(GroovyIndex.java:128)
   at org.netbeans.modules.groovy.editor.api.GroovyIndex.getClassesFromPackage(GroovyIndex.java:113)
   at org.netbeans.modules.groovy.editor.completion.TypesCompletion.complete(TypesCompletion.java:192)
   at org.netbeans.modules.groovy.editor.completion.ProposalsCollector.completeTypes(ProposalsCollector.java:106)
   at org.netbeans.modules.groovy.editor.api.completion.CompletionHandler.complete(CompletionHandler.java:162)
   at org.netbeans.modules.csl.editor.completion.GsfCompletionProvider$JavaCompletionQuery.addCodeCompletionItems(GsfCompletionProvider.java:626)
   at org.netbeans.modules.csl.editor.completion.GsfCompletionProvider$JavaCompletionQuery.resolveCompletion(GsfCompletionProvider.java:613)
   at org.netbeans.modules.csl.editor.completion.GsfCompletionProvider$JavaCompletionQuery.access$400(GsfCompletionProvider.java:250)
   at org.netbeans.modules.csl.editor.completion.GsfCompletionProvider$JavaCompletionQuery$1.run(GsfCompletionProvider.java:336)
   at org.netbeans.modules.parsing.impl.TaskProcessor.callUserTask(TaskProcessor.java:609)
   at org.netbeans.modules.parsing.api.ParserManager$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$2.call(TaskProcessor.java:201)
   at org.netbeans.modules.masterfs.filebasedfs.utils.FileChangedManager.priorityIO(FileChangedManager.java:176)
   at org.netbeans.modules.masterfs.providers.ProvidedExtensions.priorityIO(ProvidedExtensions.java:360)
   at org.netbeans.modules.parsing.nb.DataObjectEnvFactory.runPriorityIO(DataObjectEnvFactory.java:141)
   at org.netbeans.modules.parsing.impl.Utilities.runPriorityIO(Utilities.java:88)
   at org.netbeans.modules.parsing.impl.TaskProcessor.runUserTask(TaskProcessor.java:201)
   at org.netbeans.modules.parsing.api.ParserManager.parse(ParserManager.java:104)
   at org.netbeans.modules.csl.editor.completion.GsfCompletionProvider$JavaCompletionQuery.query(GsfCompletionProvider.java:345)
   at org.netbeans.spi.editor.completion.support.AsyncCompletionTask.run(AsyncCompletionTask.java:223)
   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)