I noticed that the package org.jboss.mx.util is located in different jar files in my jboss installation. jboss/client/jbossall-client.jar jboss/client/jmx-client.jar jboss/lib/jboss-jmx.jar Because the container object is represented by a MBeanProxy object (located in these packages) and the ClassCastException occurs in that class, I am beginning to think that there is some sort of conflict going on. I tried to remove jboss/client/jbossall-client.jar jboss/client/jmx-client.jar to see what happened. No luck. Still the ClassCastException. Why this exception? I dont even have to assign the object to a reference. Just by doing container.getContext() an exception is thrown. How can I retrieve the context from the PortalObjectContainer? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4034636#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...