Argh. Prior to 4.2.1 there was a bug in that logging that resulted in only the exception message being logged instead of the full stack trace. If you can reproduce with 4.2.1 or later I can see more information, otherwise all I can tell you is that the webapp is trying to read a session out of the cache and it's failing. What com.sssw.fw.exception.xxxx is I of course have no idea. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4218789#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...