Larian Studios Forums Divinity: Original Sin 2 - The Modding Dungeon Divinity - Original Sin 2 - Modding Troubleshooting Instances in level templates only in editor

That error occurs (editor only) when the instance groups (behind the scenes, every used visual is put in a separate group) are being read from file, and it attempts to merge the same level template multiple times with that group.

Are you by any chance placing the same level template multiple times?

Also: Does it work if you explode the level template? (Not that that is a useful solution, but it might help us rule out some possible issues).