finally found the solution. earlier i just added the hibernate-entitymanager.jar, javaassist.jar to the class path of the entire application not individually and i was also not adding the hibernate3.jar. now i included hibernate-entitymanager.jar, javaassist.jar and hibernate3.jar to the class path of both the client and ejb module separately. then deleted all the old jar files, emptied the tmp folder, restarted the server, rebuilt all the packages, redeployed the application and executed the client. it worked fine! thanks View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4011739#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...