Have you listed the entity in your persistence.xml?
glassfish_at_javadesktop.org wrote:
> I have built the sample Java SE application from the book "Pro EJB 3, Java Persistence AP" successfully but when running, it throws java.lang.IllegalArgumentException telling me that "Object: sepersistence.Employee[id=158] is not a known entity type". The problem is caused by the persist operation called on my entity manager.
> What's the problem ?
> [Message sent by forum member 'recursion' (recursion)]
>
> http://forums.java.net/jive/thread.jspa?messageID=287830
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: users-unsubscribe_at_glassfish.dev.java.net
> For additional commands, e-mail: users-help_at_glassfish.dev.java.net
>
>