save file making the game crash

when i updated the game it kept crashing a few seconds into the main menu loading. i took out all my mods and repaired, it kept crashing. then i removed my save files and it loaded. put my mods back in without my save files and it loaded fine again. but when i put my main save back in, it crashes. ive tried recovering the save file, but even that crashes as well. how do i fix my save file? ive had it for years