java.lang.ClassNotFoundException: org.netbeans.spi.java.project.support.ui.PackageViewChildren$PackageNode
   at java.awt.datatransfer.DataFlavor.tryToLoadClass(DataFlavor.java:0)
   at java.awt.datatransfer.DataFlavor.initialize(DataFlavor.java:0)
   at java.awt.datatransfer.DataFlavor.<init>(DataFlavor.java:0)
   at org.huberb.nbwordcount.WordCountingDropTargetListener.<init>(WordCountingDropTargetListener.java:56)
   at org.huberb.nbwordcount.WordCountTopComponent.<init>(WordCountTopComponent.java:49)
   at sun.reflect.NativeConstructorAccessorImpl.newInstance0(NativeConstructorAccessorImpl.java:0)
   at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:0)
   at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:0)
   at java.lang.reflect.Constructor.newInstance(Constructor.java:0)
   at org.openide.windows.TopComponent$Replacer.readObject(TopComponent.java:1812)
   at sun.reflect.NativeMethodAccessorImpl.invoke0(NativeMethodAccessorImpl.java:0)
   at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:0)
   at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:0)
   at java.lang.reflect.Method.invoke(Method.java:0)
   at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:0)
   at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:0)
   at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:0)
   at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:0)
   at java.io.ObjectInputStream.readObject(ObjectInputStream.java:0)
   at org.netbeans.modules.settings.convertors.XMLSettingsSupport$SettingsRecognizer.readSerial(XMLSettingsSupport.java:549)
   at org.netbeans.modules.settings.convertors.XMLSettingsSupport$SettingsRecognizer.instanceCreate(XMLSettingsSupport.java:581)
   at org.netbeans.modules.settings.convertors.SerialDataConvertor$SettingsInstance.instanceCreate(SerialDataConvertor.java:426)
   at org.netbeans.core.windows.persistence.PersistenceManager.getTopComponentPersistentForID(PersistenceManager.java:571)
   at org.netbeans.core.windows.persistence.PersistenceManager.getTopComponentForID(PersistenceManager.java:681)
   at org.netbeans.core.windows.PersistenceHandler.getTopComponentForID(PersistenceHandler.java:489)
   at org.netbeans.core.windows.PersistenceHandler.load(PersistenceHandler.java:156)
   at org.netbeans.core.windows.WindowSystemImpl.load(WindowSystemImpl.java:81)
   at org.netbeans.core.GuiRunLevel$InitWinSys.run(GuiRunLevel.java:231)
   at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:0)
   at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:0)
   at java.awt.EventQueue.access$200(EventQueue.java:0)
   at java.awt.EventQueue$3.run(EventQueue.java:0)
   at java.awt.EventQueue$3.run(EventQueue.java:0)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:0)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:0)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:159)
   at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:0)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:0)
   at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:0)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:0)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:0)
   at java.awt.EventDispatchThread.run(EventDispatchThread.java:0)