Can you check what your save is in "\AppData\Roaming\Godot\app_userdata\Feed The Void"If there is no game.res file, then it is missing. You can rename a backup file to game.res if there are backups.
Hi, I have a similar problem (not update related). There is no Feed The Void save file in my AppData even though I used the save and quit option on my dowloaded copy of the game.