Hi all, If you get this exception in Intellij IDEA, then make sure there is no javaee.jar library on project class path. IDEA automatically adds this library to j2ee project/module and it's sure thing incompatible with jboss client libraries. Just in hope you wouldn't spend whole weekend battling with classloading and jar versions ;-) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3988683#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...