Larian Studios Forums Divinity II The Dragon Knight Saga / Flames of Vengeance (English) Technical problems Any solution to 'Debug: dd67e9d19a31ce71...etc'

Nah, it's simple.

There is Divinity 2 : Ego Draconis.

Then came out Flame of Vengeance, which is the add-on for Ego Draconis.
When the addon came out, larian created Dragon Knight Saga, which is Ego Draconis + Flames of Vengeance (game + addon all in one DVD pack).

Some time ago, they created DKS Developpers Cut, which is Dragon Knight Saga and a couple bonuses.

It's all incremental.