I had the same issue and was able to fix it by deleting the Larian Studios folder in the appdata>local folder then relaunching the game
This fixed this issue for me
Fixed a lot for me. Wasn't even able to start, not after clean install.
Even reinstalled steam, changed the install folder, and various things more. All to no avail.
I noticed I had a folder named 'LarianStudio' and one named 'Larian Studio'.
Don't know how that came to be, certainly not my doing, but after removing both evrything worked fine.
