Hello, I also had the same problem. I think that when the engine was asking you to locate the Data folder, you have selected the classic one.
Pay attention to not select "Steam\steamapps\common\Divinity Original Sin 2\Data" folder, that's the classic one,
instead select "Steam\steamapps\common\Divinity Original Sin 2\DefEd\Data" folder.
Once you have selected the wrong one it will just crash when you trie to start it. There was a way to change the path, but I don't remember sorry, best suggestion i can give is to reinstall the engine and select the right folder when it asks again.

Hope it will help you smile