When you try to set an attribute in the session that is not serializable, it will throw an exception with a stack trace. So the first thing I would probably do is open up gcsMenu.jsp and goto line 450 and see if you are putting an object into the session. If so, I then would open that object and make sure that it implements Serializable. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4058475#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...