This is a gameplay crash. I am a level 63 Orc Wearwolf playing the Dawnguard side of the DLC. I am attempting to start the "Touching the Sky" quest at Darkfall Cave. Everytime I enter the cave the game freezes before it can load. I have rebooted, cleared my cache, reloaded Dawnguard, dismissed Serana, and tried rolling back my save to before I was given the quest. No other location does this that I've found, but since it is part of the main DG quest line, it is imperative I figure something out. I'd be perfectly happy to go back as far as I need to if I knew what caused the glitch, but I haven't seen anyone else on this forum with the same exact problem.