java.lang.IllegalStateException: originalSource org.openide.explorer.view.OutlineView$OutlineViewOutline[,0,0,452x0,alignmentX=0.0,alignmentY=0.0,border=,flags=251658728,maximumSize=,minimumSize=,preferredSize=,autoCreateColumnsFromModel=true,autoResizeMode=AUTO_RESIZE_SUBSEQUENT_COLUMNS,cellSelectionEnabled=false,editingColumn=-1,editingRow=-1,gridColor=javax.swing.plaf.ColorUIResource[r=212,g=208,b=200],preferredViewportSize=java.awt.Dimension[width=450,height=400],rowHeight=22,rowMargin=1,rowSelectionAllowed=true,selectionBackground=java.awt.Color[r=182,g=182,b=182],selectionForeground=javax.swing.plaf.ColorUIResource[r=0,g=0,b=0],showHorizontalLines=true,showVerticalLines=false] has no root pane: null
   at org.openide.explorer.view.DropGlassPane.putBackOriginal(DropGlassPane.java:131)
   at org.openide.explorer.view.OutlineViewDragSupport.dragDropEnd(OutlineViewDragSupport.java:112)
   at java.awt.dnd.DragSourceContext.dragDropEnd(DragSourceContext.java:435)
   at sun.awt.dnd.SunDragSourceContextPeer$EventDispatcher.run(SunDragSourceContextPeer.java:491)
   at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
   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)