jboss-messaging-client.jar is not intended to be used in a managed environment. It is a convenience library to be used on the client side, when a remote client connects to a JBoss Messaging server. If you access JBoss Messaging from an application running inside the JBoss application server, you need to deploy that application in the same class loading domain as the JBoss Messaging instance. If you give me more details about what you are trying to do, I might be able to help you further. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3978939#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...