java.lang.NullPointerException
        at java.awt.Container.addImpl(Container.java:1045)
        at java.awt.Container.add(Container.java:365)
        at org.netbeans.modules.form.layoutdesign.support.SwingLayoutBuilder.createLayout(SwingLayoutBuilder.java:172)
        at org.netbeans.modules.form.layoutdesign.support.SwingLayoutBuilder.setupContainerLayout(SwingLayoutBuilder.java:107)
        at org.netbeans.modules.form.VisualReplicator.setupContainerLayout(VisualReplicator.java:815)
        at org.netbeans.modules.form.VisualReplicator.cloneComponent(VisualReplicator.java:747)
        at org.netbeans.modules.form.VisualReplicator.cloneComponent(VisualReplicator.java:727)
        at org.netbeans.modules.form.VisualReplicator.cloneComponent(VisualReplicator.java:727)
        at org.netbeans.modules.form.VisualReplicator.createClone(VisualReplicator.java:182)
        at org.netbeans.modules.form.VisualReplicator.createClone(VisualReplicator.java:170)
        at org.netbeans.modules.form.FormDesigner$FormListener.run(FormDesigner.java:2222)
        at org.netbeans.modules.form.FormLAF$3.run(FormLAF.java:320)
        at org.openide.util.Mutex.doEventAccess(Mutex.java:1355)
        at org.openide.util.Mutex.readAccess(Mutex.java:268)
        at org.netbeans.modules.form.FormLAF.executeWithLookAndFeel(FormLAF.java:305)
        at org.netbeans.modules.form.FormDesigner$FormListener.processEvents(FormDesigner.java:2205)
        at org.netbeans.modules.form.FormDesigner$FormListener.formChanged(FormDesigner.java:2171)
        at org.netbeans.modules.form.FormDesigner.updateWholeDesigner(FormDesigner.java:537)
        at org.netbeans.modules.form.FormDesigner.initialize(FormDesigner.java:313)
        at org.netbeans.modules.form.FormDesigner.componentShowing(FormDesigner.java:1800)
        at org.netbeans.core.multiview.MultiViewPeer.showCurrentElement(MultiViewPeer.java:295)
        at org.netbeans.core.multiview.MultiViewPeer.showCurrentElement(MultiViewPeer.java:265)
        at org.netbeans.core.multiview.MultiViewPeer$SelectionListener.selectionChanged(MultiViewPeer.java:673)
        at org.netbeans.core.multiview.MultiViewModel.fireSelectionChanged(MultiViewModel.java:243)
        at org.netbeans.core.multiview.MultiViewModel.setActiveDescription(MultiViewModel.java:115)
        at org.netbeans.core.multiview.MultiViewModel$BtnGroup.setSelected(MultiViewModel.java:293)
        at javax.swing.JToggleButton$ToggleButtonModel.setSelected(JToggleButton.java:237)
        at javax.swing.ButtonGroup.setSelected(ButtonGroup.java:147)
        at org.netbeans.core.multiview.MultiViewModel$BtnGroup.setSelected(MultiViewModel.java:289)
        at org.netbeans.core.multiview.TabsComponent$ButtonMouseListener.mousePressed(TabsComponent.java:444)
        at java.awt.AWTEventMulticaster.mousePressed(AWTEventMulticaster.java:263)
        at java.awt.AWTEventMulticaster.mousePressed(AWTEventMulticaster.java:262)
        at java.awt.Component.processMouseEvent(Component.java:6260)
        at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
        at java.awt.Component.processEvent(Component.java:6028)
        at java.awt.Container.processEvent(Container.java:2041)
        at java.awt.Component.dispatchEventImpl(Component.java:4630)
        at java.awt.Container.dispatchEventImpl(Container.java:2099)
        at java.awt.Component.dispatchEvent(Component.java:4460)
        at java.awt.LightweightDispatcher.retargetMouseEvent(LightweightDispatcher.java:4574)
        at java.awt.LightweightDispatcher.processMouseEvent(LightweightDispatcher.java:4235)
        at java.awt.LightweightDispatcher.dispatchEvent(LightweightDispatcher.java:4168)
        at java.awt.Container.dispatchEventImpl(Container.java:2085)
        at java.awt.Window.dispatchEventImpl(Window.java:2475)
        at java.awt.Component.dispatchEvent(Component.java:4460)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
        at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:117)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)