ClassCastException with two times the same class: anonymous wrote : javax.ejb.TransactionRolledbackLocalException: Exception thrown from bean; nested exception is: java | .lang.ClassCastException: org.hibernate.collection.PersistentBag | java.lang.ClassCastException: org.hibernate.collection.PersistentBag This tells me that you have two different versions of the class that is used. Two imports of hibernate jars, something like that... View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4067921#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...