Hi, I have the same error when I want to deploy my app on JBP 2.6.1. My app uses Myfaces, Seam and portlet and works well under JBP 2.6.0 CR2 + JB 4.0.5 GA I did exactly what you wrote, Dean, and now I have a new exception: | java.lang.IllegalArgumentException: Class org.jboss.seam.jsf.SeamApplicationFactory is no javax.faces.application.ApplicationFactory | I'm sure that my EAR contains only on time the both myFaces jar (myfaces-impl.jar and myfaces-api.jar) in appli.war/WEB-INF/lib Thanks for your help. JP View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4069698#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...