If you're getting the error message at exactly the same moment everytime, chances are you have some missing files in the game folder in Program Files. The game is probably trying to find a certain file, can't do it, and can't proceed without it, and then crashes. Possibly something went wrong when you might've added some mods. If that is the case, the only thing I can recommend is making a backup of the save files and reinstall the game, unless you can find and restore all the original files pre-modding.
First thing you might want to try though, is the Savefix mod from RDDev. If it doesn't work, you might have to give my method a try. Hope that helps you.