Did you try verifying local files? In the Steam library, right click on Divinity Original Sin and select Properties, switch to the Local Files tab and then click on the 'Verify Integrity of Game Cache...' button.
Please email email@example.com, with a description of the problem and the report.zip file generated by the D:OS support tool
(for the PC version). The report will contain system and game information, any crash dumps, and your saved games. If file size is an issue, any saves not related to the problem can be deleted; if this is consistent for you, you would only need to leave one save (I could not reproduce this in previous or new saves).