Receiving the same error when attempting to save. I was originally wondering if it is because I my 'my documents' is located on a NAS drive, but less sure now.

However, one thing to note, Larian, in my 'my documents' directory I see two paths for save games:

\\NETGEARNAS\data\Files\Documents\Documents\Larian Studios\Divinity Original Sin\Savegames

&

\\NETGEARNAS\data\Files\Documents\Documents\Larian Studios\Divinity Original Sin\NETGEARNAS\data\Files\Documents\Documents\Larian Studios\Divinity Original Sin\Savegames

The UNC name is also mapped to a drive letter.