When it works, the ClassLoader used is: | getClassLoader: org.jboss.mx.loading.UnifiedClassLoader3@1d2300e{ url=file:/opt/jboss-4.2.3.GA/server/all/tmp/deploy/tmp7477Navineo.ear ,addedOrder=45} When it fails, the ClassLoader used is: | DummyTacheEgoiste1HAS/getClassLoader: org.jboss.mx.loading.UnifiedClassLoader3@183d59c{ url=null ,addedOrder=20} The problem is obviously that url=null so the ear classes are unknown. But what can i do about it? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4207619#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...