Good evening, i get the above exception when using Hibernate with JSF, i saw it many times in the past and the root cause was that like this
Sorry to necro this, but I thought that since this wasn't marked as answered perhaps it would be OK. Others may have fallen victim to the same pitfall as I.
I recently ran into similar problems after merging some HBM's. Subsequently, I had issues regarding JNDI and sessionFactory look-up failures due to duplicate class mappings in the HBM files causing the JNDI/SessionFactory service to be unable to start up..
So, as a start - make sure you are not declaring duplicate classes in your mapping files :)
This may or may not be what someone looking at this question needs, but it was my issue :)