When you post exception stack traces, please post the whole thing, including the logging info. The excerpt you posted means nothing and at this point I cannot tell if that is because you didn't include the interesting stuff, or because this is yet another poorly-worded exception. In some cases it helps to include a few log lines before and after the exception. (You could start JBoss AS without your app deployed, and once the "started in xxx seconds" message shows, then deploy your app. Any log entries after the "started in" entry could be of interest.) You could try setting -verbose:class JVM option. This option causes the JVM to print out each class loaded and the JAR from which it was loaded. This might give some clues as to why things are going wrong - look for classes being loaded from unexpected locations. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4225157#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...