This normally happens because you are using Seam 1.2 and have forgotten to update your dtd references View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4044414#4044414 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=4044414