Comment 2 for bug 1693335

The problem is the hide_server_addresses extension is looking for the instance in the request cache using the id passed in via the client, which is upper case, and the id key in the cache is from the db, which is lower-case, so it doesn't find the instance and blows up with a TypeError because it's not checking for None. This is something you'll hit with mysql which is case insensitive so it can find the instance but doesn't cache it using the same key.