Steve Ebersole commented on an issue
Hibernate ORM / Bug HHH-8534
Metamodel#managedType(SomeMappedSuperclass.class) returns null
This should have been addressed in HHH-6896 but the JPA 2.1 TCK is showing a failure for this. Need to investigate.

Ahhh. In the JPA TCK case its a MappedSuperclass with no Entity...