OK, so this looks a little bit involved. The CNFE seems to occur when MyFaces deserializes the component tree. I don't see why MyFaces would have serialized your component into the tree? Are you using the evil Tomahawk stuff (I have seen Tomahawk try to do that to some users, I think.) Are you using client-side conversations? The log also shows an NPE also occurring. I suppose you are saying that the CNFE actually happens first and is the cause of the NPE? From the look of the stack traces that might be possible. The thing is that the NPE is occurring on a line of code that doesn't exist in the lastest Seam 1.1 codebase. So are you using an older build of 1.1? What happens if you grab the very latest revision of the code? Is there still an NPE? What line number? Are you able to produce a very minimal stripped-down runnable test case that reproduces this? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3979702#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...