I was getting a similar error the other day (Seam Beta 1). It was occurring when using a rich:tabPanel. I was using ajax switching for the tabs and it was on a particular tab I getting errors. It only happened after I refactored a monolithic xhtml file to use facelet templating. I never got it resolved (other than to switch to client side switching) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4085196#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...