java.lang.AssertionError: Lookup.lookup(NotificationDisplayer.class) has to return the same instance NotificationDisplayer.
   at org.openide.awt.NotificationDisplayer.getDefault(NotificationDisplayer.java:95)
   at org.netbeans.modules.uihandler.SlownessReporter$NotifySnapshot.<init>(SlownessReporter.java:158)
   at org.netbeans.modules.uihandler.SlownessReporter.notifySlowness(SlownessReporter.java:141)
   at org.netbeans.modules.uihandler.UIHandler.publish(UIHandler.java:117)
   at java.util.logging.Logger.log(Logger.java:522)
   at java.util.logging.Logger.doLog(Logger.java:543)
   at java.util.logging.Logger.log(Logger.java:607)
   at org.netbeans.core.TimableEventQueue$1R.run(TimableEventQueue.java:253)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1411)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:1991)
Caused: org.openide.util.RequestProcessor$SlowItem: task failed due to: java.lang.AssertionError: Lookup.lookup(NotificationDisplayer.class) has to return the same instance NotificationDisplayer.
   at org.openide.util.RequestProcessor.post(RequestProcessor.java:428)
   at org.netbeans.core.TimableEventQueue.report(TimableEventQueue.java:262)
   at org.netbeans.core.TimableEventQueue.done(TimableEventQueue.java:194)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:165)
   at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:211)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:128)
   at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:117)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:113)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:105)
   at java.awt.EventDispatchThread.run(EventDispatchThread.java:90)