hey folks. i had the same problem with an ejb3-client on jboss 4.0.5 earlier i always used all jars within the jboss/client folder. but now i'm switching to maven and here you are advised to define everey single jar, your project depends on. so for my test-client i had to add the following jars as dependency: jbossall-client.jar jboss-ejb3-client.jar jboss-aop-jdk50-client.jar jboss-aspect-jdk50-client.jar only then i got my client running and calling the ejb3. it seems that as long as you don't provide the correct jars, the client tries to load through "JBoss RMI Classloader" and here we go... View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4148935#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...