Can't seem to find any Larian local files under My Docs???
It should be '..\Documents\Larian Studios\Divinity Original Sin'
Have you moved your My Documents folder somewhere other than the default? (different hard drive or NAS) In that case you would also find your profile not being saved when you restart the game, rather than 'just' crashing when trying to save.
Im having the same problem. Those files are nowhere to be found where you say they should be.