@ghepardo, I came to the conclusion that it's not possible to use CallByReference between 2 ears with classloader isolation. You have to enable CallByValue, this makes class translation between classloaders possible through the use of Java serialization. See this: http://www.jboss.org/community/wiki/classloadingconfiguration. I tried both options suggested in this article. I was able to make it work only with CallByValue=true in EARDeployer though... The other option failed with the familiar: anonymous wrote : Invalid invocation, check your deployment packaging message. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4254443#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...