The earlier error (with a location of STDERR) are expected, The Sun JSF implementation is writing text to stderr, which is reported by log4j and error output. The last error means that you probably have the myfaces jar file bundled with your application. You should remove it because jbossas already comes with the sun faces implementation. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4144663#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...