anonymous wrote : Exception in thread "main" java.lang.UnsupportedClassVersionError: Bad version number in .class file | Actually, this isn't specific to EJB3 or tuning of EJB3 :) I guess you compiled some class (or classes) using a higher version of Java (Java 1.6?) and are using it in a server running on a lower version of Java (Java 1.5?) View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4266224#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...