Hi, I think 'session cannot be found' can happen as I explained. To further verify my reasoning, you can try to find in the server's server.log if there is something like: "A problem has been detected with the connection to remote client xxxxxxxxx, jmsClientID=xxxxxxxx. It is possible the client has exited without closing its connection(s) or the network has failed. All associated connection resources will be cleaned up." If not, then I think the connection is probably shared by two or more threads, and one of the thread closed the connection without waiting for other threads finish their work with it. That should be viewed as an application level issue from JBM angle. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4234520#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...