java.lang.NullPointerException
   at org.netbeans.modules.form.layoutdesign.support.SwingLayoutBuilder.fillGroup(SwingLayoutBuilder.java:287)
   at org.netbeans.modules.form.layoutdesign.support.SwingLayoutBuilder.composeGroup(SwingLayoutBuilder.java:242)
   at org.netbeans.modules.form.layoutdesign.support.SwingLayoutBuilder.fillGroup(SwingLayoutBuilder.java:270)
   at org.netbeans.modules.form.layoutdesign.support.SwingLayoutBuilder.composeGroup(SwingLayoutBuilder.java:242)
   at org.netbeans.modules.form.layoutdesign.support.SwingLayoutBuilder.fillGroup(SwingLayoutBuilder.java:261)
   at org.netbeans.modules.form.layoutdesign.support.SwingLayoutBuilder.composeGroup(SwingLayoutBuilder.java:242)
   at org.netbeans.modules.form.layoutdesign.support.SwingLayoutBuilder.fillGroup(SwingLayoutBuilder.java:270)
   at org.netbeans.modules.form.layoutdesign.support.SwingLayoutBuilder.composeGroup(SwingLayoutBuilder.java:242)
   at org.netbeans.modules.form.layoutdesign.support.SwingLayoutBuilder.createLayout(SwingLayoutBuilder.java:179)
   at org.netbeans.modules.form.layoutdesign.support.SwingLayoutBuilder.removeComponentsFromContainer(SwingLayoutBuilder.java:136)
   at org.netbeans.modules.form.VisualReplicator.removeComponent(VisualReplicator.java:547)
   at org.netbeans.modules.form.FormDesigner$FormListener.run(FormDesigner.java:2644)
   at org.netbeans.modules.form.FormLAF$3.run(FormLAF.java:333)
   at org.openide.util.Mutex.doEventAccess(Mutex.java:1376)
   at org.openide.util.Mutex.readAccess(Mutex.java:278)
   at org.netbeans.modules.form.FormLAF.executeWithLookAndFeel(FormLAF.java:316)
   at org.netbeans.modules.form.FormDesigner$FormListener.processEvents(FormDesigner.java:2538)
   at org.netbeans.modules.form.FormDesigner$FormListener.formChanged(FormDesigner.java:2504)
   at org.netbeans.modules.form.FormModel.fireEvents(FormModel.java:1327)
   at org.netbeans.modules.form.FormModel.fireEventBatch(FormModel.java:1300)
   at org.netbeans.modules.form.FormModel.firePendingEvents(FormModel.java:1263)
   at org.netbeans.modules.form.FormModel.access$000(FormModel.java:68)
   at org.netbeans.modules.form.FormModel$2.run(FormModel.java:1240)
   at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:312)
   at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:733)
   at java.awt.EventQueue.access$200(EventQueue.java:103)
   at java.awt.EventQueue$3.run(EventQueue.java:694)
   at java.awt.EventQueue$3.run(EventQueue.java:692)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:703)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:159)
   at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
   at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
   at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)