ZK - Open Source Ajax Java Framework

com.liferay.portal.kernel.deploy.hot.HotDeployException: Error registering portlets for ISUI-portlet
        at com.liferay.portal.kernel.deploy.hot.BaseHotDeployListener.throwHotDeployException(BaseHotDeployListener.java:45)
        at com.liferay.portal.deploy.hot.PortletHotDeployListener.invokeDeploy(PortletHotDeployListener.java:104)
        at com.liferay.portal.kernel.deploy.hot.HotDeployUtil._doFireDeployEvent(HotDeployUtil.java:109)
        at com.liferay.portal.kernel.deploy.hot.HotDeployUtil._fireDeployEvent(HotDeployUtil.java:183)
        at com.liferay.portal.kernel.deploy.hot.HotDeployUtil.fireDeployEvent(HotDeployUtil.java:38)
        at com.liferay.portal.kernel.servlet.PortletContextListener.doPortalInit(PortletContextListener.java:99)
        at com.liferay.portal.kernel.util.BasePortalLifecycle.portalInit(BasePortalLifecycle.java:42)
        at com.liferay.portal.kernel.util.PortalLifecycleUtil.register(PortalLifecycleUtil.java:61)
        at com.liferay.portal.kernel.util.PortalLifecycleUtil.register(PortalLifecycleUtil.java:51)
        at com.liferay.portal.kernel.util.BasePortalLifecycle.registerPortalLifecycle(BasePortalLifecycle.java:50)
        at com.liferay.portal.kernel.servlet.PortletContextListener.contextInitialized(PortletContextListener.java:55)
        at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:3910)
        at org.apache.catalina.core.StandardContext.start(StandardContext.java:4393)
        at org.jboss.web.tomcat.service.deployers.TomcatDeployment.performDeployInternal(TomcatDeployment.java:310)
        at org.jboss.web.tomcat.service.deployers.TomcatDeployment.performDeploy(TomcatDeployment.java:142)
        at org.jboss.web.deployers.AbstractWarDeployment.start(AbstractWarDeployment.java:461)
        at org.jboss.web.deployers.WebModule.startModule(WebModule.java:118)
        at org.jboss.web.deployers.WebModule.start(WebModule.java:97)
        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.jboss.mx.interceptor.ReflectedDispatcher.invoke(ReflectedDispatcher.java:157)
        at org.jboss.mx.server.Invocation.dispatch(Invocation.java:96)
        at org.jboss.mx.server.Invocation.invoke(Invocation.java:88)
        at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:264)
        at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:668)
        at org.jboss.system.microcontainer.ServiceProxy.invoke(ServiceProxy.java:206)
        at $Proxy38.start(Unknown Source)
        at org.jboss.system.microcontainer.StartStopLifecycleAction.installAction(StartStopLifecycleAction.java:42)
        at org.jboss.system.microcontainer.StartStopLifecycleAction.installAction(StartStopLifecycleAction.java:37)
        at org.jboss.dependency.plugins.action.SimpleControllerContextAction.simpleInstallAction(SimpleControllerContextAction.java:62)
        at org.jboss.dependency.plugins.action.AccessControllerContextAction.install(AccessControllerContextAction.java:71)
        at org.jboss.dependency.plugins.AbstractControllerContextActions.install(AbstractControllerContextActions.java:51)
        at org.jboss.dependency.plugins.AbstractControllerContext.install(AbstractControllerContext.java:348)
        at org.jboss.system.microcontainer.ServiceControllerContext.install(ServiceControllerContext.java:286)
        at org.jboss.dependency.plugins.AbstractController.install(AbstractController.java:1631)
        at org.jboss.dependency.plugins.AbstractController.incrementState(AbstractController.java:934)
        at org.jboss.dependency.plugins.AbstractController.resolveContexts(AbstractController.java:1082)
        at org.jboss.dependency.plugins.AbstractController.resolveContexts(AbstractController.java:984)
        at org.jboss.dependency.plugins.AbstractController.change(AbstractController.java:822)
        at org.jboss.dependency.plugins.AbstractController.change(AbstractController.java:553)
        at org.jboss.system.ServiceController.doChange(ServiceController.java:688)
        at org.jboss.system.ServiceController.start(ServiceController.java:460)
        at org.jboss.system.deployers.ServiceDeployer.start(ServiceDeployer.java:163)
        at org.jboss.system.deployers.ServiceDeployer.deploy(ServiceDeployer.java:99)
        at org.jboss.system.deployers.ServiceDeployer.deploy(ServiceDeployer.java:46)
        at org.jboss.deployers.spi.deployer.helpers.AbstractSimpleRealDeployer.internalDeploy(AbstractSimpleRealDeployer.java:62)
        at org.jboss.deployers.spi.deployer.helpers.AbstractRealDeployer.deploy(AbstractRealDeployer.java:50)
        at org.jboss.deployers.plugins.deployers.DeployerWrapper.deploy(DeployerWrapper.java:171)
        at org.jboss.deployers.plugins.deployers.DeployersImpl.doDeploy(DeployersImpl.java:1439)
        at org.jboss.deployers.plugins.deployers.DeployersImpl.doInstallParentFirst(DeployersImpl.java:1157)
        at org.jboss.deployers.plugins.deployers.DeployersImpl.doInstallParentFirst(DeployersImpl.java:1178)
        at org.jboss.deployers.plugins.deployers.DeployersImpl.install(DeployersImpl.java:1098)
        at org.jboss.dependency.plugins.AbstractControllerContext.install(AbstractControllerContext.java:348)
        at org.jboss.dependency.plugins.AbstractController.install(AbstractController.java:1631)
        at org.jboss.dependency.plugins.AbstractController.incrementState(AbstractController.java:934)
        at org.jboss.dependency.plugins.AbstractController.resolveContexts(AbstractController.java:1082)
        at org.jboss.dependency.plugins.AbstractController.resolveContexts(AbstractController.java:984)
        at org.jboss.dependency.plugins.AbstractController.change(AbstractController.java:822)
        at org.jboss.dependency.plugins.AbstractController.change(AbstractController.java:553)
        at org.jboss.deployers.plugins.deployers.DeployersImpl.process(DeployersImpl.java:781)
        at org.jboss.deployers.plugins.main.MainDeployerImpl.process(MainDeployerImpl.java:702)
        at org.jboss.system.server.profileservice.repository.MainDeployerAdapter.process(MainDeployerAdapter.java:117)
        at org.jboss.system.server.profileservice.hotdeploy.HDScanner.scan(HDScanner.java:362)
        at org.jboss.system.server.profileservice.hotdeploy.HDScanner.run(HDScanner.java:255)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
        at java.util.concurrent.FutureTask$Sync.innerRunAndReset(FutureTask.java:317)
        at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:150)
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$101(ScheduledThreadPoolExecutor.java:98)
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.runPeriodic(ScheduledThreadPoolExecutor.java:180)
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:204)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
        at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.ClassCastException: org.zkoss.zk.ui.http.DHtmlLayoutPortlet cannot be cast to javax.portlet.Portlet
        at com.liferay.portlet.PortletBagFactory.create(PortletBagFactory.java:120)
        at com.liferay.portal.deploy.hot.PortletHotDeployListener.initPortlet(PortletHotDeployListener.java:466)
        at com.liferay.portal.deploy.hot.PortletHotDeployListener.doInvokeDeploy(PortletHotDeployListener.java:253)
        at com.liferay.portal.deploy.hot.PortletHotDeployListener.invokeDeploy(PortletHotDeployListener.java:101)