Hey guys, Looks like this is still an issue for EJB3 / JBoss 4.0.5 GA. Not sure why, the EJB3 spec clearly says (emphasis added): 4.2.1 Instance Passivation and Conversational State | | The Bean Provider is required to ensure that the PrePassivate method leaves the instance fields and the fields of its associated interceptors ready to be serialized by the container. The objects that are assigned to the instance?s non-transient fields and the non-transient fields of its interceptors after the PrePassivate method completes must be one of the following. | | - A serializable object. | - A null. | - A reference to an enterprise bean?s business interface. | - A reference to an enterprise bean?s remote interface, even if the stub class is not serializable. | - A reference to an enterprise bean?s remote home interface, even if the stub class is not serializable. | - A reference to an entity bean?s local interface, even if it is not serializable. | - A reference to an entity bean?s local home interface, even if it is not serializable. | - A reference to the SessionContext object, even if it is not serializable. | - A reference to the environment naming context (that is, the java:comp/env JNDI context) | or any of its subcontexts. | - A reference to the UserTransaction interface. | - A reference to a resource manager connection factory. | - A reference to a container-managed EntityManager object, even if it is not serializable. | | ... | I'm seeing a lot of stack traces during SFSB passivation, but most of the time the app server just hangs. The transient SessionContext did not work for me. Not sure what the problem is. Hmm... View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4003383#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...