I have the same problem my horse's oats is negative 2 Billions. I was searching for a mod version of grim soul in which i can increase my horse level quickly ( I tried a mod in which this was possible) so I can level up my horse quickly and go to North parts ,so I tried few apps and one of those caused me this problem and i uninstalled that app and i don't remember where I downloaded the app and what mod was that, I am regularly feeding my horse a lot of oats to make its energy to normal but it will take a lot of time and days. Somebody help me , i don't want to make a new game I'd.
