This doesn't appear to be related to Seam. From this error it looks like you have different versions of your classes on your client and server. You also appear to be mixing RMI, EJB 2.x and EJB 3. I suggest using pure EJB 3 with Seam. Try looking at an EJB 3 tutorial and/or an EJB 3 book (free one here: http://www.theserverside.com/tt/books/wiley/masteringEJB3/index.tss). While you may eventually get EJB 3 to recognize this code due to the annotations, it's confusing to look at. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3961661#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...