java.lang.ClassCastException
	at com.sun.java.swing.plaf.gtk.SynthMenuItemUI.getPreferredMenuItemSize(SynthMenuItemUI.java:411)
	at com.sun.java.swing.plaf.gtk.SynthMenuItemUI.getPreferredSize(SynthMenuItemUI.java:317)
	at javax.swing.JComponent.getPreferredSize(JComponent.java:1275)
	at javax.swing.BoxLayout.checkRequests(BoxLayout.java:429)
	at javax.swing.BoxLayout.preferredLayoutSize(BoxLayout.java:246)
	at javax.swing.plaf.basic.DefaultMenuLayout.preferredLayoutSize(DefaultMenuLayout.java:38)
	at java.awt.Container.preferredSize(Container.java:1178)
	at java.awt.Container.getPreferredSize(Container.java:1162)
	at javax.swing.JComponent.getPreferredSize(JComponent.java:1277)
	at org.netbeans.core.windows.frames.DefaultContainerImpl.showPopupMenu(DefaultContainerImpl.java:1064)
	at org.netbeans.core.windows.frames.TabHandlePopupListener$1.run(TabHandlePopupListener.java:121)
	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:178)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:454)
[catch] at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:201)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:145)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:137)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:100)