It should fix the missing variables when it updates an older save to a newer version... But probably something went wonky, though I think I can suspect why
if a player rolls back after loading a save, it will undo the updates, but allow the player to continue. Now that I think about it, this is probably why there are often so many bugs after a new release. I'll fix this for the next update, so that rollback after load game is disabled if something's updated. It's an inconvenience, but I'm afraid a necessary one.