&quot;bill.burke(a)jboss.com&quot; wrote : This is what has to be unique: | | | | <property name="jboss.entity.manager.factory.jndi.name" value="java:/itsEntityManagerFactory"/> | | | | The unit name does not have to be unique between EARs. | | Why is this happening? the jboss.entity.manager.factory.jndi.name binds to global JNDI. | | Ok - so after thinking about this for a while and walking the Seam examples and my applications, I believe I see what you are talking about. I need to set the jndi name for each persistent unit (the property you highlighted) to be unique across the ear applications. To reiterate for myself, the reason is that the jndi name needs to be unique across the application server instance. I am getting the exception because both applications are trying to bind to the same jndi name. And that is why one "failed" to deploy; yet the application still worked (it found the other one that was previously deployed). I will try that out tomorrow. I'm sure it's a cut/paste issue. I followed the Seam examples and then copied my skeleton to new applications without realizing this property also needs to be changed. And since I don't have enough experience with an application server, I'm not sure I every would have figured this out. Thanks for looking at this, -- jc View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3968271#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...