Well, the line numbers in your stack trace above are from a 4.0.3 version of jboss-jmx.jar, not the 4.0.4.GA version. So, there's any extra copy of that jar somewhere. Perhaps you copied it to server/all/lib? The only thing to do to upgrade 4.0.4.GA to use JBC 1.4.0.SP1 is to replace jboss-cache.jar in server/all/lib. If you put any other jars from the JBC distribution on the classpath anywhere, you should undo that change. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3976113#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...