Thanks for the reply. So this is definitely a version mismatch error on the serialized class, so that is obviously is the problem. However I can't find any documentation that lists what client jars I need to include per version. In 3.2.x it was jbossall-client.jar. This jar doesn't exist for Jboss 4.x in the maven repository, what jars are required to have the class with the correct serialization id? I tried jboss-client and jbossmq-client, but this doesn't have the NamingContextFactory. Thanks, Todd View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4056166#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...