I had the problem once. The only way I found to get rid of it, was to delete the saves until I found one without the problem. In the end it was such a setback that I started a new character. I still don't know where it came from and I'm still not sure if what I did was right. You might also want to allocate more space to your swap file or update your drivers. I was also toying with those when the problem disappeared. One thing I'm sure of is, on a new character with the same mods, I did not encounter the crash anymore on a place I had it 100% of time with the other character.