I think you'll find the problem comes from the namespace. JBossXB returns null when it doesn't recognise the root element. It is expecting a root element of: {jboss-namespace}:jboss but since it is using the dtd, it is actually getting {}:jboss i.e. no namspace. JBossXB should be fixed generically to throw a message like :jboss is not a root element {jboss-namespace}:jboss but equally, JBossXB should be able to "fixup" the namespace for the case when one isn't provided if you know upfront what the namespace should be. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4094716#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...