Larian Studios Forums Divinity: Original Sin 2 Divinity - Original Sin 2 - Game Master DOS2 No Longer Recognizing GM Campaign

Have you deleted folder with savegames in documents too?

All campaigns created and saved in prepare mode are stored in
"Documents\Larian Studios\Divinity Original Sin 2\GMCampaigns"

If you was launching campaign in Play mode - then your saved progress can be found in
"Documents\Larian Studios\Divinity Original Sin 2\PlayerProfiles\<ProfileName>\Savegames\GM"