There're a few possibilities about what exactly is happening.
Some mods can really crash the game, even thought it's rare and hard, as i use over 10 and the game is working properly. So i suppose (don't be offended, it's just a supposition) that your game isn't original and maybe it's missing files, however if it's actually original, i suggest you to verify files and apply the latest patch if it wasn't updated yet, if still doesn't work, maybe you could try share your savegame with someone and get him/her to test, if it doesn't work, then it's something on your save sadly. I can't help you with that at moment tho. =/