java.util.ConcurrentModificationException
        at java.util.IdentityHashMap$IdentityHashMapIterator.nextIndex(IdentityHashMap.java:715)
        at java.util.IdentityHashMap$KeyIterator.next(IdentityHashMap.java:804)
        at org.netbeans.modules.timers.InstanceWatcher.contains(InstanceWatcher.java:78)
        at org.netbeans.modules.timers.InstanceWatcher.add(InstanceWatcher.java:72)
        at org.netbeans.modules.timers.TimesCollectorPeer$ObjectCountDescripton.add(TimesCollectorPeer.java:214)
        at org.netbeans.modules.timers.TimesCollectorPeer$ObjectCountDescripton.access$000(TimesCollectorPeer.java:189)
        at org.netbeans.modules.timers.TimesCollectorPeer.reportReference(TimesCollectorPeer.java:104)
        at org.netbeans.modules.timers.Install$TimerHandler.publish(Install.java:132)
        at java.util.logging.Logger.log(Logger.java:472)
        at java.util.logging.Logger.doLog(Logger.java:494)
        at java.util.logging.Logger.log(Logger.java:558)
        at org.netbeans.modules.editor.hints.AnnotationHolder.getPosition(AnnotationHolder.java:960)
        at org.netbeans.modules.editor.hints.AnnotationHolder.setErrorDescriptionsImpl(AnnotationHolder.java:861)
        at org.netbeans.modules.editor.hints.AnnotationHolder.access$1200(AnnotationHolder.java:110)
        at org.netbeans.modules.editor.hints.AnnotationHolder$4.run(AnnotationHolder.java:801)
        at org.netbeans.editor.BaseDocument.render(BaseDocument.java:1362)
        at org.netbeans.modules.editor.hints.AnnotationHolder.setErrorDescriptions(AnnotationHolder.java:798)
        at org.netbeans.modules.editor.hints.HintsControllerImpl.setErrorsImpl(HintsControllerImpl.java:105)
        at org.netbeans.modules.editor.hints.HintsControllerImpl.setErrors(HintsControllerImpl.java:87)
        at org.netbeans.spi.editor.hints.HintsController$1.run(HintsController.java:73)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:572)
        at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:997)