User development, A new message was posted in the thread "EJB3 Session Bean Container error": http://community.jboss.org/message/528897#528897 Author : Juliano Vidal Profile : http://community.jboss.org/people/julianovidal Message: -------------------------------------------------------------- Hey man!   After build a new EJB project and ran it in another JBoss 5.1, I got it working. When I ran in my old one I found that it did not work. So I started to seach for it's diferences. I added a jar: *jboss-aspect-jdk50-client.jar* in my common/lib beacuse I was getting a ClassDefNotFoundException exception. And the solution I found was to copy that jar from the JBoss 4.2.3 to the JBoss 5.1.0   That caused the Countainer error... After I removed it from the common/lib I got that working!!   The error I was getting before did not appear again.... yet...   Thanks for your help! -------------------------------------------------------------- To reply to this message visit the message page: http://community.jboss.org/message/528897#528897