java.lang.OutOfMemoryError: GC overhead limit exceeded
   at java.util.LinkedHashMap.keySet(LinkedHashMap.java:532)
   at java.util.HashSet.iterator(HashSet.java:172)
   at org.openide.filesystems.EventControl.invokeDispatchers(EventControl.java:219)
   at org.openide.filesystems.EventControl.exitAtomicAction(EventControl.java:188)
   at org.openide.filesystems.EventControl.finishAtomicAction(EventControl.java:116)
   at org.openide.filesystems.FileSystem.finishAtomicAction(FileSystem.java:545)
   at org.openide.filesystems.MultiFileObject.refresh(MultiFileObject.java:551)
   at org.openide.filesystems.AbstractFolder.check(AbstractFolder.java:664)
   at org.openide.filesystems.AbstractFolder.getFileObjectImpl(AbstractFolder.java:479)
   at org.openide.filesystems.AbstractFolder.getFileObject(AbstractFolder.java:475)
   at org.openide.filesystems.FileObject.getFileObject(FileObject.java:987)
   at org.netbeans.core.startup.preferences.PropertiesStorage.toPropertiesFile(PropertiesStorage.java:309)
   at org.netbeans.core.startup.preferences.PropertiesStorage$4.fileChanged(PropertiesStorage.java:388)
   at sun.reflect.GeneratedMethodAccessor6.invoke(GeneratedMethodAccessor6.java:0)
   at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
   at java.lang.reflect.Method.invoke(Method.java:497)
   at org.openide.util.WeakListenerImpl$ProxyListener.invoke(WeakListenerImpl.java:487)
   at com.sun.proxy.$Proxy1.fileChanged(.java:0)
   at org.openide.filesystems.FCLSupport$DispatchEventWrapper.dispatchEventImpl(FCLSupport.java:178)
   at org.openide.filesystems.FCLSupport$DispatchEventWrapperMulti.dispatchAllEventsSync(FCLSupport.java:248)
   at org.openide.filesystems.FCLSupport$DispatchEventWrapper.dispatchEvent(FCLSupport.java:137)
   at org.openide.filesystems.FCLSupport.dispatchEvent(FCLSupport.java:112)
   at org.openide.filesystems.FileObject$ED.dispatch(FileObject.java:1435)
   at org.openide.filesystems.FileSystem$EventDispatcher.run(FileSystem.java:795)
   at org.openide.filesystems.EventControl.dispatchEvent(EventControl.java:84)
   at org.openide.filesystems.FileSystem.dispatchEvent(FileSystem.java:554)
   at org.openide.filesystems.FileObject.dispatchEvent(FileObject.java:644)
   at org.openide.filesystems.FileObject.fireFileChangedEvent(FileObject.java:612)
   at org.openide.filesystems.AbstractFolder.fileChanged1(AbstractFolder.java:586)
   at org.openide.filesystems.MultiFileObject.fileChanged(MultiFileObject.java:1507)
   at sun.reflect.GeneratedMethodAccessor6.invoke(GeneratedMethodAccessor6.java:0)
   at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)