But how did the karma variable, which was a dictionary, turn into an int instead? You don't think this is also related to the rollback errors, do you?* NEW VERSION*
For others with the karma error, i made a quick and dirty fix.
Place the fixKarmaOnLoad.rpy in the game folder\game and run the game. load the save and your karma will reset to default if the value is the older version.
Don't forget to save.
You can leave the file in the directory. It only changes it on load... but don't roll back before the scene or it will break again.