Hi, can you please post the list of jars you've added? I've looked into the MANIFEST of jbossall-cient.jar, but there's no CLASSPATH at all (only some vendor specific information). And I think that I've the same problem. I'm using JBoss 4.2.3 GA. Here's my console output: | Exception in thread "main" java.lang.ClassCastException: $Proxy1 | at org.jboss.naming.client.java.javaURLContextFactory$EncContextProxy.invoke(javaURLContextFactory.java:129) | at $Proxy0.lookup(Unknown Source) | at javax.naming.InitialContext.lookup(Unknown Source) | at de.my.class.MyFailingClass.main(MyFailingClass.java:22) | TIA, Ralf View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4187206#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...