We have installed jboss-4.0.5.GA-EJB3 using JEMS installer. Then we installed JbossMessaging-1.2.0.GA into the above configuration using the install script bundled with the JbossMessaging-1.2.0.GA distribution. ant -f release-admin.xml On Running examples bundled with the distribution, the queue example works fine. However, trying to run ejb3MDB example fails throwing java.lang.RuntimeException: java.lang.ClassNotFoundException: No ClassLoaders found for: org.jboss.jms.client.container. ClosedInterceptor Interestingly, if you first run the MDB (not Ejb3MDB) example, it runs successfully although there is an exception in the server. Once you have run this example and there is the mdb-example.jar in the deploy directory, subsequent tests even with ejb3MDB work fine. So we have left mdb-example.jar in the deploy directory. Now even if the server is restarted ejb3mdb continue to work fine. This is kind of a hack but I thought it will be useful to share it with other users View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4028813#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...