java.lang.AssertionError
	at org.netbeans.modules.form.layoutdesign.support.SwingLayoutBuilder.fillGroup(SwingLayoutBuilder.java:173)
	at org.netbeans.modules.form.layoutdesign.support.SwingLayoutBuilder.composeGroup(SwingLayoutBuilder.java:142)
	at org.netbeans.modules.form.layoutdesign.support.SwingLayoutBuilder.fillGroup(SwingLayoutBuilder.java:163)
	at org.netbeans.modules.form.layoutdesign.support.SwingLayoutBuilder.composeGroup(SwingLayoutBuilder.java:142)
	at org.netbeans.modules.form.layoutdesign.support.SwingLayoutBuilder.createLayout(SwingLayoutBuilder.java:112)
	at org.netbeans.modules.form.layoutdesign.support.SwingLayoutBuilder.removeComponentsFromContainer(SwingLayoutBuilder.java:95)
	at org.netbeans.modules.form.VisualReplicator.removeComponent(VisualReplicator.java:404)
	at org.netbeans.modules.form.FormDesigner$FormListener.run(FormDesigner.java:1392)
	at org.netbeans.modules.form.FormLAF$2.run(FormLAF.java:94)
	at org.openide.util.Mutex.doEventAccess(Mutex.java:1146)
	at org.openide.util.Mutex.readAccess(Mutex.java:183)
	at org.netbeans.modules.form.FormLAF.executeWithLookAndFeel(FormLAF.java:76)
	at org.netbeans.modules.form.FormDesigner$FormListener.formChanged(FormDesigner.java:1326)
	at org.netbeans.modules.form.FormModel.fireEvents(FormModel.java:886)
[catch] at org.netbeans.modules.form.FormModel$EventBroker.run(FormModel.java:989)
	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:461)
	at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:242)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:163)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:157)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:149)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:110)