java.lang.IllegalArgumentException: A node selection cannot contain nodes (jButton1 [JButton]) not underneath the root (Form NewFrame).
        at org.openide.explorer.ExplorerManager.checkUnderRoot(ExplorerManager.java:561)
        at org.openide.explorer.ExplorerManager.access$300(ExplorerManager.java:87)
        at org.openide.explorer.ExplorerManager$1AtomicSetSelectedNodes.checkArgumentIsValid(ExplorerManager.java:232)
        at org.openide.explorer.ExplorerManager$1AtomicSetSelectedNodes.run(ExplorerManager.java:265)
        at org.openide.util.Mutex.readAccess(Mutex.java:362)
        at org.openide.explorer.ExplorerManager.setSelectedNodes(ExplorerManager.java:272)
        at org.netbeans.modules.form.FormDesigner$3.propertyChange(FormDesigner.java:282)
        at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:339)
        at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:347)
        at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:276)
        at java.awt.Component.firePropertyChange(Component.java:7868)
        at org.openide.windows.TopComponent.setActivatedNodesImpl(TopComponent.java:319)
        at org.openide.windows.TopComponent.access$400(TopComponent.java:112)
        at org.openide.windows.TopComponent$SynchronizeNodes.run(TopComponent.java:1565)
        at org.openide.windows.TopComponent$SynchronizeNodes.resultChanged(TopComponent.java:1547)
        at org.openide.util.lookup.ProxyLookup.setLookups(ProxyLookup.java:159)
        at org.openide.explorer.DefaultEMLookup.updateLookups(DefaultEMLookup.java:131)
        at org.openide.explorer.DefaultEMLookup.propertyChange(DefaultEMLookup.java:163)
        at org.openide.util.WeakListenerImpl$PropertyChange.propertyChange(WeakListenerImpl.java:186)
        at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:339)
        at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:276)
        at org.openide.explorer.ExplorerManager$2.run(ExplorerManager.java:842)
        at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:597)
        at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:104)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:273)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:183)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:173)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:168)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:160)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:121)