Obviously, you have a classloader problem, which you might solve by putting some JBoss system libraries (jboss-jmx.jar, and what else is needed by that one) on the system classpath (i.e. add them to the jboss classpath in the run.sh or run.bat file). However, normally this should not be necessary when using a 'normal' java 5 VM, so still you should explain to us what you did to get this exception.... View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3999203#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...