You'll need to recompile your web application making sure to link to your current jboss runtime environment during compilation. (keep the new environment on the classpath during compilation). Otherwise, it's compiled against a different set of classes than you're trying to get it to run with. I'm not sure about the rest of your problems, but what I've just said is the solution to this one. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4119840#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...