Hi, The class loading is failing at your tomcat instance. Taking a look at WebClassLoader: http://www.jdocs.com/tomcat/6.0.14/org/apache/catalina/loader/WebappClass... We can see that the illegal state is being thrown because the method stop of WebClassLoader was called at some point in the past, causing the started field to become false. Thus, when loadClass method checks for started filed value and sees it is false, it throws the exception: 1241 // Log access to stopped classloader | 1242 if (!started) { | 1243 try { | 1244 throw new IllegalStateException(); | 1245 } catch (IllegalStateException e) { | 1246 log.info(sm.getString("webappClassLoader.stopped", name), e); | 1247 } | 1248 } This hardly has anything to do with JBoss AOP. You need to find out what is triggering the call to WebappClassLoader.stop(), which happens before JBoss AOP tries to load the class. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4238574#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...