OK, I've been a bit fast to post .... But it seems a bit weird for me... So, I add a factoryClass="com.mycompany.classloaders.MasterClassLoader" attribute to the constructor tag... I don't get this error anymore. It seems a bit strange that if a factory class is not provided, the system does not use Object class as default factory... Thanks for having read me... View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4191750#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...