EJB3 Persistence Spec 6.2.1 has samples that do not include a DTD or XSD declaration. Section 7.1.1 is a bit vauge as to whether the descriptor requires this information: anonymous wrote : When the container finds a persistence.xml file, it processes the persistence unit definitions that it contains. The container must validate the persistence.xml file against the persistence_1_0.xsd schema and report any validation errors. In any case, we'll need a more friendly error message to give the bean provider some sense of why the deployment failed. S, ALR View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4157220#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...