I could solve this problem by including a portlet-api-lib (don't know where I found it). But after that I ran into other problems while serializing/deserializing the session and marked some members as transient where necessary (the SessionContext for example). But there were still problems when using the session 5 minutes before timeout. Now I use Seam 1.1 and ICEfaces 1.5.1 and after the application works as before the migration I'll check this problem again. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3989976#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...