Larian Studios Forums Divinity II The Dragon Knight Saga / Flames of Vengeance (English) Divinity II - Flames of Vengeance Open Letter to Larian Support

That's incorrect.
Saves from DKS will not work with FoV, only saves from DKS will work with DKS. FoV is an addon and compatible with ED only. And only saves from the same language version of ED will be compatible with FoV (german <-> german, english <-> english).