So, I've completed the Dark Brotherhood questline, but I neglected to retrieve the Stone of Barenziah from the Dark Brotherhood Sanctuary. Now when I try to enter the Sanctuary it just glitches in the loading screen every time. I need the stone to complete the "No Stone Unturned" quest. Is there a way I can get the stone another way? Or can I enter the Sanctuary without it glitching?
This is a rare bug. There's no other way to get the stone (except for the console), but the bug was fixed in version 184.108.40.206.8 of the Official Skyrim Patch, which was released March 4th, 2013. So if you update, you should be able to enter the Sanctuary and retrieve the gem fine.