Your DmWebSession class must be your problem then. Saying it implements Serializable is insufficient; all of its fields must also implement Serializable or be declared transient. Somewhere in the DmWebSession's object graph there is a non-transient reference to the session itself (aka org.apache.catalina.session.StandardSessionFacade). StandardSessionFacade isn't serializable, so that won't work. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4038717#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...