java.lang.AssertionError
   at org.netbeans.modules.masterfs.filebasedfs.children.ChildrenSupport.removeChild(ChildrenSupport.java:125)
   at org.netbeans.modules.masterfs.filebasedfs.children.ChildrenSupport.rescanChildren(ChildrenSupport.java:234)
   at org.netbeans.modules.masterfs.filebasedfs.children.ChildrenSupport.refresh(ChildrenSupport.java:162)
   at org.netbeans.modules.masterfs.filebasedfs.fileobjects.FolderObj$FolderChildrenCache.refresh(FolderObj.java:564)
   at org.netbeans.modules.masterfs.filebasedfs.fileobjects.FolderObj.refreshImpl(FolderObj.java:353)
   at org.netbeans.modules.masterfs.filebasedfs.fileobjects.BaseFileObj.refresh(BaseFileObj.java:680)
   at org.netbeans.modules.masterfs.filebasedfs.fileobjects.FolderObj.refresh(FolderObj.java:438)
   at org.netbeans.modules.masterfs.filebasedfs.fileobjects.RefreshSlow$1.run(RefreshSlow.java:77)
   at org.netbeans.modules.masterfs.filebasedfs.utils.FileChangedManager.idleIO(FileChangedManager.java:179)
   at org.netbeans.modules.masterfs.filebasedfs.fileobjects.RefreshSlow$1.run(RefreshSlow.java:84)
   at org.openide.filesystems.FileUtil$2.run(FileUtil.java:576)
   at org.openide.filesystems.EventControl.runAtomicAction(EventControl.java:125)
   at org.openide.filesystems.FileSystem.runAtomicAction(FileSystem.java:542)
   at org.openide.filesystems.FileUtil.runAtomicAction(FileUtil.java:560)
   at org.openide.filesystems.FileUtil.runAtomicAction(FileUtil.java:580)
   at org.netbeans.modules.masterfs.filebasedfs.fileobjects.RefreshSlow.refreshFileObject(RefreshSlow.java:88)
   at org.netbeans.modules.masterfs.filebasedfs.fileobjects.FileObjectFactory.refresh(FileObjectFactory.java:512)
   at org.netbeans.modules.masterfs.filebasedfs.fileobjects.FileObjectFactory.refresh(FileObjectFactory.java:487)
   at org.netbeans.modules.masterfs.filebasedfs.fileobjects.FileObjectFactory.refreshAll(FileObjectFactory.java:434)
   at org.netbeans.modules.masterfs.filebasedfs.fileobjects.FileObjectFactory$1.run(FileObjectFactory.java:693)
   at org.netbeans.modules.masterfs.filebasedfs.FileBasedFileSystem.runAsInconsistent(FileBasedFileSystem.java:105)
   at org.netbeans.modules.masterfs.filebasedfs.fileobjects.FileObjectFactory.refresh(FileObjectFactory.java:700)
   at org.netbeans.modules.masterfs.filebasedfs.fileobjects.RootObj.invokeRefreshFor(RootObj.java:194)
   at org.netbeans.modules.masterfs.filebasedfs.fileobjects.RefreshSlow.run(RefreshSlow.java:64)
   at org.netbeans.core.ui.warmup.MenuWarmUpTask$NbWindowsAdapter.run(MenuWarmUpTask.java:298)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1418)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:1957)
Caused: org.openide.util.RequestProcessor$SlowItem: task failed due to: java.lang.AssertionError
   at org.openide.util.RequestProcessor$Task.schedule(RequestProcessor.java:1456)
   at org.netbeans.core.ui.warmup.MenuWarmUpTask$NbWindowsAdapter.windowActivated(MenuWarmUpTask.java:157)
   at java.awt.AWTEventMulticaster.windowActivated(AWTEventMulticaster.java:373)
   at java.awt.AWTEventMulticaster.windowActivated(AWTEventMulticaster.java:372)
   at java.awt.Window.processWindowEvent(Window.java:1874)
   at javax.swing.JFrame.processWindowEvent(JFrame.java:274)
   at java.awt.Window.processEvent(Window.java:1820)
   at java.awt.Component.dispatchEventImpl(Component.java:4714)
   at java.awt.Container.dispatchEventImpl(Container.java:2143)
   at java.awt.Window.dispatchEventImpl(Window.java:2475)
   at java.awt.Component.dispatchEvent(Component.java:4544)
   at java.awt.KeyboardFocusManager.redispatchEvent(KeyboardFocusManager.java:1850)
   at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(DefaultKeyboardFocusManager.java:910)
   at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:409)
   at java.awt.Component.dispatchEventImpl(Component.java:4586)
   at java.awt.Container.dispatchEventImpl(Container.java:2143)
   at java.awt.Window.dispatchEventImpl(Window.java:2475)
   at java.awt.Component.dispatchEvent(Component.java:4544)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:635)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:137)
   at java.awt.SentEvent.dispatch(SentEvent.java:55)
   at java.awt.DefaultKeyboardFocusManager$DefaultKeyboardFocusManagerSentEvent.dispatch(DefaultKeyboardFocusManager.java:183)
   at java.awt.DefaultKeyboardFocusManager.sendMessage(DefaultKeyboardFocusManager.java:210)
   at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:286)
   at java.awt.Component.dispatchEventImpl(Component.java:4586)
   at java.awt.Container.dispatchEventImpl(Container.java:2143)
   at java.awt.Window.dispatchEventImpl(Window.java:2475)
   at java.awt.Component.dispatchEvent(Component.java:4544)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:635)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:137)
   at java.awt.SequencedEvent.dispatch(SequencedEvent.java:101)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:633)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:137)
   at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:296)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:211)
   at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:201)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:196)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:188)
   at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)