Unable to enter Inner Sanctum in Forgotten Vale

Every time I open that door the system freezes. I've installed, uninstalled, downloaded, deleted, redownloaded the expansion, nothing works. At this point I am unable to continue to content because I can't get the bow. Has anyone else come across this and possibly found a solution?

No but my Xbox 360 crashed about three times during the Harkon battle.

For those who may come across this as well, I was finally able to resolve it. Apparently I just had to fast travel around the world for a few days (I think it was 5 days later by the time I got back). And to Colonel, yeah I ran into that too, right after I got past this and fought him, it crashed 3 or 4 times before I (Serana actually got the final blow) finally downed him without issue. It's a shame, that's quite irritating and almost game breaking if one is not patient enough.

What difficulty did you face him on by the way, I tried facing him on Master but gave up and killed him on adept because he was too hard to kill. I think i was level 21 at the time. He just kept going into mist form and regenerating health after it took me ages to get him to half health in the first place only to heal himself back up because it was hard attacking him because he moves around constantly and absorbs health when attacking. I ended up sneaking attacking him because i got bored of wasting my time. I couldn't even hit him properly because of the fact he kept moving around yet despite this he managed to keep draining health from me and i eventually had to revert to human form to use potions which made it even harder lol.

I was on master. My char was lvl 61 though. Didn't ever see him use anything but bats. I first thought to only use the bow cause of the "it's supposed to be uber against undead" aspect, that idea flopped with a resounding thud. Then tried going Lord to Lord with him, that ended significantly worse. Eventually I ended up, using my normal dragonbone gear (sword with paralyze 2sec enchant, he'd resist a lot, but it's made with a black gem and has like 138ish charges on it so I can swing it for days before it runs out and 2 secs may not seem like much, but it's enough to cause them to fall down and force them to go through the stand up animation, buying you an extra few seconds without the added cost) poisoned every swing (stam and magic poisons, he's immune to health poisons), and just used the terrain to hide from his shots then run him down swinging when he tried to get snippy and come out of running around. When I'd lash at him and land a few crits he'd kind of freak out and go bats trying to run away, then he'd run and suck health off serana and try to run me down, so I'd run and heal her till she retook aggro. Also used a Storm Atronoch since that helps depleat his magic and is a targeted ranged mob, so when I lost sight of him I just look where stormy's shootin, he's also a good aggro distraction. The key for me seemed to be keeping the atronoch up and using my main weapons instead of the new stuff from the expansion. Everything I made was like 3 times stronger than anything I found so not much use. I think he only did that bubble thing 3 times before he went down, and we killed him before he got it activated the third time. Also don't forget shouts, Unrelenting force doesn't do much (since he's flying) but fire breath put a boot in his balls (steel toed). Flame cloak is nice too, not sure it contributed much to the fight, but it was a nice additive when he was chasing me to close, still taking damage, but I can run and regen at the same time. Hope that helps.

I also have the same problem. Every time i enter the inner sanctum he game crashed a minute later. Before i made it to the sanctum it was constantly freezing over and over for a couple seconds at a time. I reinstalled and am running vanilla skyrim and it is still crashing. I also cannot acquire the dragon shout in the lost vale. i see it there but it wont transfer to me. I have like 240 some hours in and the character im currently using is a 51. i hope there is some way to fix this

I crashed ONCE when entering the sanctum. And ive had the crashes before when they wont stop it happened like every 20 minutes. i just stopped playing for a while and it fixed