It looks to me like you have the Project.class in both EAR files. JBoss is giving you an instance of Project that has a class definition loaded from a different classloader than the Project you are trying to cast to. My first suggestion for fixing that would be to not bundle any of the app1-*.*ar archives in app2. (be careful to make sure app1 deploys before app2) That *should* solve the problem. Assuming it does, then we can talk about other ways to package your apps if you want to do something different. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3997380#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...