Guilds in this region cannot be auto-managed

I’m trying to set my guild to Automatic as it’s set to Manual.
All I get when using “Roster Management Style” is “Guilds in this region cannot be auto-managed” is there a way around this?

Unify - [EU - Giantstalker]

Hey. Classic does not have an Armory or an API, so Guilds cannot be auto-managed as there is no info to pull.