I spent some time on this today with my local version of JBoss-5 Beta4. A bit of debugging and some modification to the JBoss server code (to print out some logs) pointed to a file named exposed.beans which is present in the META-INF folder of hudson.war/WEB-INF/lib/hudson-core-1.200.jar/META-INF folder. Apparently while parsing/opening this file there's some problem which leads to these exceptions. I haven't exactly been able to figure out what exactly is wrong with this file. As a workaround (just for tests) i deleted this file from the META-INF folder and deployed the application. The application deployed successfully without problems. I was even able to deploy the hudson.war file in an archive format (after deleting the exposed.beans file). I still don't exactly know what's the problem with the exposed.beans. Maybe you would want to point this to someone who's involved in developing Hudson (not sure whether they would entertain this request because you are using a Beta server and their documentation mentions using JBoss-4.2.x)? P.S: If you are going to delete the exposed.beans for testing, you will also have to delete the HUDSON.SF from hudson.war/META-INF folder (remember this just for testing), or else the war file will fail verification (since this is a signed jar). View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4138980#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...