I only noticed this after Dawnguard was installed, but now I cannot get to the Shrine of Mehrunes Dagon. I am right about to finish the quest "Pieces of the Past" where you must assemble the pieces of Mehrune's Razor, I am at the point where I have to go meet Silus, but when I go anywhere near the shrine I get a CTD. Apparently this does not happen if you do the quest before the Dragons come out, but sadly I am a little farther along the main questline than that (retrieve the horn of windcaller). The same person who said this, also said that it also happened before the Daedric quest was activated.
I know it has nothing to do with mods, as I have done a clean re-install, verified the integrity of my files* (steam), disabled and re-enabled one mod at a time, and still it CTD. A part of the area affected is the Skyborn Altar as well as the Lord Stone.
*I had to do this once before, as I was getting repeated CTD from going to certain towns, it detected 3 files that were corrupted and replaced them, but the second time nothing was amiss.
I am at a loss of what to try.