[jboss-user] [EJB 3.0] - Re: org.hibernate.MappingException: could not instantiate id

I have managed to fix this by adding the following to persistence.xml on the persistence unit: | <class>org.debtbase.server.entitybeans.LegacyObject</class> | <exclude-unlisted-classes>true</exclude-unlisted-classes> | The ID generator does not seem to be created now. The exception has gone, and the @Entity bean on this Persistence Unit works properly. I would dearly like to know why explicitly listing the class has made a difference as it is only excluding Entity Beans from a different persistence unit. This is the third hint I have got during my debugging that different persistence units may be exposed to all of the Entity Beans in the application. Can anyone offer any insight into multiple persistence units and ID generators? Is this cross-PU effect supposed to be so? Regards Matt View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4095555#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...