I don't recall anyone else reporting something like this. Maybe a corrupt save or profile config file?

If reinstalling doesn't help, try moving the save out of the savegames folder.

Try browsing to the '..\Documents\Larian Studios' folder and renaming the 'Divinity Original Sin' subfolder.
This folder contains the saved games, configuration files and a level cache folder. Deleting or renaming it will get the game to recreate it on startup; playing the game from a different Windows user account would effectively do the same thing.
After that, see if you can start D:OS; if so, exit and then copy/move some or all of your (non-edited) saves from the renamed folder into the newly created profile's savegames folder.
If the game still crashes, delete the new My Documents D:OS folder and rename the original back again.

Once you get it working, you can make a backup of the install folder, so if you ever need to re-install Windows, etc, you can restore the game without having to re-download.