We are using Tapestry 4.0.2, which, in turn, uses javassist-3.0, under JBoss 4.0.4.GA. Everytime we redeploy our EAR, we start getting NotFoundExceptions from javassist. I found an old Tapestry Jira issue for the same problem, and they wrote it off as a JBoss problem, but it seems to me like more of an issue of interaction between javassist and JBoss classloading. As far as I can tell the exception occurs any time javassist looks for a class provided by a jar that was changed in the redeployment. Has anyone else seen this? Is there perhaps a work-around? The problem goes away when the app server is restarted, but it is a pain to re-start the server every time we re-deploy. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3973645#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...