Do you mean copy the jar files from the 4.03 endorsed dir to 4.0.1sp1 endorsed dir? If so, I tried that, but that doesn't work because jboss is using these jar files on startup. When I copied these jars to this directory it will not start up. Or do you mean copy the jar files from the 4.0.3 endorsed dir to my application directory? I am not for sure what version of xerces that 4.0.1 is using, but I would think it is using a different version to what I need. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3976410#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...