I agree its classloading related. As I said, I can take a look, but i'm not convinced I would have any more luck than you! So, this is how I lay it out: 1) Use the default JBoss (4.0.5.GA) install (so myfaces in jsf-libs) 2) Put everything I can, especially the jars that provide UI (so jsf-facelets, trinidad, seam-ui, seam-mail, seam-pdf - specifically anything with a faces-config.xml in it I suppose) in the war/WEB-INF/lib 3) Put all the rest in the ear and reference from application.xml (so now I have drools, jbpm, el, jboss-seam.jar and then internal shared stuff there) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4017642#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...