Found an issue in SessionFactoryImpl.close() where cacheAccess.close() is called twice. This results in interactions with the JCache CacheManager which are invalid because it will have been closed after the first invocation.

While there is something in place to simply log when the cache manager is closed twice, this does not apply here since before reaching that point, tentatives are made to destroy known caches. And that is the operation illegal at that point.

Unless this should be filed as a separate issue, I plan to add a commit to the pull request fixing that duplicate call.
See https://github.com/hibernate/hibernate-orm/blob/master/hibernate-core/src/main/java/org/hibernate/internal/SessionFactoryImpl.java#L737