Portal迁移错误

portal迁移后，点击管理，portlet管理，portlet此 portlet 暂时被禁用。
EJPAQ9400E: struts 中发生内部异常。  查看详细信息

com.ibm.portal.WpsException: EJPAQ9400E: Internal exception in struts.

        at com.ibm.wps.portlets.portletmanager.actions.UnknownErrorAction.execute(UnknownErrorAction.java:188)

        at com.ibm.wps.portlets.struts.WpsRequestProcessor.processActionPerform(WpsRequestProcessor.java:355)

        at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:274)

        at com.ibm.wps.portlets.struts.WpsRequestProcessor.processNewActionUri(WpsRequestProcessor.java:943)

        at com.ibm.wps.portlets.struts.WpsStrutsUtil.createViewCommand(WpsStrutsUtil.java:830)

        at com.ibm.wps.portlets.struts.WpsStrutsUtil.processException(WpsStrutsUtil.java:2726)

        at com.ibm.wps.portlets.struts.WpsStrutsUtil.executeCommand(WpsStrutsUtil.java:1450)

        at com.ibm.wps.portlets.struts.WpsStrutsUtil.executeCommand(WpsStrutsUtil.java:1334)

        at com.ibm.wps.portlets.struts.WpsStrutsUtil.executeSavedCommand(WpsStrutsUtil.java:1252)
后台异常信息：Caused by: java.lang.ClassNotFoundException: com.ibm.wps.command.plm.QueryPLMCommand        at java.net.URLClassLoader.findClass(URLClassLoader.java:496)        at com.ibm.ws.bootstrap.ExtClassLoader.findClass(ExtClassLoader.java:132)        at java.lang.ClassLoader.loadClass(ClassLoader.java:631)        at com.ibm.ws.bootstrap.ExtClassLoader.loadClass(ExtClassLoader.java:87)        at java.lang.ClassLoader.loadClass(ClassLoader.java:597)        at com.ibm.ws.classloader.ProtectionClassLoader.loadClass(ProtectionClassLoader.java:58)        at com.ibm.ws.classloader.ProtectionClassLoader.loadClass(ProtectionClassLoader.java:54)        at com.ibm.ws.classloader.CompoundClassLoader.loadClass(CompoundClassLoader.java:402)        at java.lang.ClassLoader.loadClass(ClassLoader.java:597)        at com.ibm.ws.classloader.CompoundClassLoader.loadClass(CompoundClassLoader.java:402)        at java.lang.ClassLoader.loadClass(ClassLoader.java:597)        at com.ibm.ws.classloader.CompoundClassLoader.loadClass(CompoundClassLoader.java:402)        at java.lang.ClassLoader.loadClass(ClassLoader.java:597)        ... 216 more
谁能告诉我为什么？