java.lang.NullPointerException
	at org.zkoss.bind.impl.AbstractRenderer.resoloveTemplate(AbstractRenderer.java:56)
	at org.zkoss.bind.impl.BindTreeitemRenderer.render(BindTreeitemRenderer.java:39)
	at org.zkoss.zul.Tree$Renderer.renderChangedItem(Tree.java:1790)
	at org.zkoss.zul.Tree$Renderer.access$4(Tree.java:1774)
	at org.zkoss.zul.Tree.renderChangedItem(Tree.java:1959)
	at org.zkoss.zul.Tree.onTreeDataContentChange(Tree.java:1412)
	at org.zkoss.zul.Tree.onTreeDataChange(Tree.java:1343)
	at org.zkoss.zul.Tree.access$12(Tree.java:1270)
	at org.zkoss.zul.Tree$3.onChange(Tree.java:1464)
	at org.zkoss.zul.AbstractTreeModel.fireEvent(AbstractTreeModel.java:108)
	at org.zkoss.zul.DefaultTreeNode.setData(DefaultTreeNode.java:121)
	at org.zkoss.jpa.examples.tree.UnitTreeViewModel.move(UnitTreeViewModel.java:103)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at org.zkoss.bind.impl.ParamCall.call(ParamCall.java:111)
	at org.zkoss.bind.impl.BinderImpl.doExecute(BinderImpl.java:1564)
	at org.zkoss.bind.impl.BinderImpl.doCommand(BinderImpl.java:1357)
	at org.zkoss.bind.impl.BinderImpl.access$8(BinderImpl.java:1333)
	at org.zkoss.bind.impl.BinderImpl$CommandEventListener.onEvent0(BinderImpl.java:1241)
	at org.zkoss.bind.impl.BinderImpl$CommandEventListener.onEvent(BinderImpl.java:1199)
	at org.zkoss.zk.ui.AbstractComponent.onEvent(AbstractComponent.java:2742)
	at org.zkoss.zk.ui.AbstractComponent.service(AbstractComponent.java:2713)
	at org.zkoss.zk.ui.AbstractComponent.service(AbstractComponent.java:2654)
	at org.zkoss.zk.ui.impl.EventProcessor.process(EventProcessor.java:136)
	at org.zkoss.zk.ui.impl.UiEngineImpl.processEvent(UiEngineImpl.java:1710)
	at org.zkoss.zk.ui.impl.UiEngineImpl.process(UiEngineImpl.java:1495)
	at org.zkoss.zk.ui.impl.UiEngineImpl.execUpdate(UiEngineImpl.java:1205)
	at org.zkoss.zk.au.http.DHtmlUpdateServlet.process(DHtmlUpdateServlet.java:600)
	at org.zkoss.zk.au.http.DHtmlUpdateServlet.doGet(DHtmlUpdateServlet.java:482)
	at org.zkoss.zk.au.http.DHtmlUpdateServlet.doPost(DHtmlUpdateServlet.java:491)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
	at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
	at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1221)
	at org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter.doFilterInternal(OpenEntityManagerInViewFilter.java:147)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
	at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
	at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:399)
	at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
	at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
	at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:766)
	at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:450)
	at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
	at org.mortbay.jetty.Server.handle(Server.java:326)
	at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
	at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:945)
	at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:756)
	at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:218)
	at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
	at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:410)
	at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)