Hi jcg3 and all, No I am not trying to make my app run with JSF RI. My app is currently running well under JBoss 4.0.5GA and Seam 1.2.1GA. I've just installed JBoss 4.2.1GA and I need to configure Seam 1.2.1GA to run under it (or may be I don't need to!). With just JBoss 4.2.1 and an usual deployment of my app, I am running into this exception: anonymous wrote : Caused by: java.lang.NoClassDefFoundError: org/apache/commons/digester/Digester In 4.0.5GA, this jar lives under jboss-4.0.5.GA\server\default\deploy\jbossweb-tomcat55.sar. I remember having to go through an exercise to copy this jar from Seam to this directory. However, with JBoss 4.2.1 this directory simply does not exist. The thing with setup is that it's usually a one time thing and I did it and forgot about it. Until migration time.... :( Thanks -tony View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4067232#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...