Seam 1.1 has a dependency to el-api and el-impl jars, which 1.0.1 did not have. Are you sure you have included those in your ear? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3987989#3987989 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=3987989