Your run.bat looks fine. The only ways I can reproduce the above error are by either: - not starting JBoss using the run.bat with your modifications - Having modified the pluggable-instrumentor.jar/META-INF/MANIFEST.MF so that it no longer contains the following: | Premain-Class: org.jboss.aop.standalone.PluggableInstrumentor | Can-Redefine-Classes: true | View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4049417#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...