No worries. I didn't really prepare anything as I thought you might just look at the stack trace, see what's wrong, have a fix and just want to try that against the project. Happy path basically. I'll see if I can get to a more concise example, but am quite packed with work myself.

Regarding the naming strategy: the population SQL worked without the change on Hibernate 4.3.8. If I upgrade to 5.0 and don't adapt I see the population failing with a message saying the column expiry_date does not exist.

A few things that might help diagnosing or at least contextualizing the new exception: completely rely on Hibernate for all schema migration and use hibernate.hbm2ddl.auto set to auto. The test cases bootstrap an EntityManagerFactory multiple times so I guess that Hibernate will try to migrate the schema it created in the first place and fail doing exactly that.