Your jibx-run-1.2.1.jar and jibx-extras-1.2.1.jar are being considered as application client deployments. Your jibx-extras-1.2.1.jar consists this classpath entry: anonymous wrote : Class-Path: jibx-run.jar xpp3.jar stax-api.jar wstx-asl.jar Notice, the jibx-run.jar (which i assume is what you meant by jibx-run.jar-1.2.1.jar). So the jibx-run.jar is picked up again through the ClassPath entry. There are some known issues with processing ClassPath entries in MANIFEST.MF of jars, in AS-5. Try removing the jibx-run.jar entry from the Classpath attribute of jibx-extras-1.2.1.jar: Class-Path: xpp3.jar stax-api.jar wstx-asl.jar View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4253649#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...