java.lang.AssertionError: Wrong diagnostic handler: com.sun.tools.javac.comp.DeferredAttr$DeferredAttrDiagHandler@77ea13cf
Thread dump:
Active Reference Queue Daemon
	java.lang.Object.wait(Native Method)
	java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:143)
	org.openide.util.lookup.implspi.ActiveQueue$Impl.removeSuper(ActiveQueue.java:93)
	org.openide.util.lookup.implspi.ActiveQueue$Daemon.run(ActiveQueue.java:131)
Framework Active Thread
	java.lang.Object.wait(Native Method)
	org.eclipse.osgi.framework.internal.core.Framework.run(Framework.java:1870)
	java.lang.Thread.run(Thread.java:745)
TimerQueue
	sun.misc.Unsafe.park(Native Method)
	java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:215)
	java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(AbstractQueuedSynchronizer.java:2078)
	java.util.concurrent.DelayQueue.take(DelayQueue.java:223)
	javax.swing.TimerQueue.run(TimerQueue.java:174)
	java.lang.Thread.run(Thread.java:745)
Worker-JM
	java.lang.Object.wait
   at com.sun.tools.javac.util.Assert.error(Assert.java:162)
   at com.sun.tools.javac.util.Assert.check(Assert.java:87)
   at com.sun.tools.javac.util.Log.popDiagnosticHandler(Log.java:444)
   at com.sun.tools.javac.api.JavacTrees.attribStatToTree(JavacTrees.java:987)
   at com.sun.tools.javac.api.JavacTrees.getAttrContext(JavacTrees.java:938)
   at com.sun.tools.javac.api.JavacTrees.getScope(JavacTrees.java:797)
   at com.sun.tools.javac.api.JavacTrees.getScope(JavacTrees.java:157)
   at org.netbeans.modules.java.completion.BaseTask.getEnvImpl(BaseTask.java:314)
   at org.netbeans.modules.java.completion.BaseTask.getCompletionEnvironment(BaseTask.java:266)
   at org.netbeans.modules.java.completion.JavaCompletionTask.resolve(JavaCompletionTask.java:269)
   at org.netbeans.modules.java.completion.BaseTask.run(BaseTask.java:93)
   at org.netbeans.modules.java.completion.JavaCompletionTask.run(JavaCompletionTask.java:80)
   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$2.call(TaskProcessor.java:201)
   at org.netbeans.modules.masterfs.filebasedfs.utils.FileChangedManager.priorityIO(FileChangedManager.java:176)
   at org.netbeans.modules.masterfs.providers.ProvidedExtensions.priorityIO(ProvidedExtensions.java:360)
   at org.netbeans.modules.parsing.nb.DataObjectEnvFactory.runPriorityIO(DataObjectEnvFactory.java:141)
   at org.netbeans.modules.parsing.impl.Utilities.runPriorityIO(Utilities.java:88)
   at org.netbeans.modules.parsing.impl.TaskProcessor.runUserTask(TaskProcessor.java:201)
   at org.netbeans.modules.parsing.api.ParserManager.parse(ParserManager.java:104)
   at org.netbeans.modules.editor.java.JavaCompletionProvider$JavaCompletionQuery.query(JavaCompletionProvider.java:234)
   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)