has had similar errors like this, of CTD around cretin areas (but very few on SSE around 5 ever since its release)
this is part of the reality of playing Skyrim, every now and then you will come across bugs (it part of life) the Unofficial Patch fixes a lot of issues and so do all the Bethesda Updates
as you can see SAVING your game is essential just so you dont have replay hours of game due to a bug or crash
so what do you do with your bug ?....if this one understands correctly you gotten past that point loading a older save? ...just keep on playing and sweep it under the carpet and hope that it was a one of glitch and not the start to a consistent patter of crashing.
Personally I play a lot and lot of hours & start new games once a month, I accept even before I start that I might have a crash or two, its only when things get real bad do I try to fix stuff, because sometimes you can wreck a game trying different solutions when you dont really need to, thats just the way this one tackles game issues
now if your using mods ........ahh thats a whole different story, and if your game is going to crash or be stable will depend on your moding skills
as to what is happening technically with your bug, has no idea way above my head