help me

Whenever i try to load my game it pauses then kicks me back to main menu. i was originally messing around with the file to try and change what i have in my cave, this is the error log : Message: There is an error in XML document (1, 3407173). InnerException: System.NullReferenceException...

I've been trying for months and my main saved game crashes every time after 10 seconds of running. Tried on another laptop and mods are removed but the problem persists. help.