After entering the Yngol Barrow the screen turns completely black, but I can still move the character. If I press start the system menu comes up, but general stats and quest menu are greyed out and I can't access them.
I can't use load either and if I press quit the game freezes. Has this happened to anyone else?

Yes. This is happening to me every single time I try and enter Yngol Barrow. I wanted to see what the coral claw I bought in Winterhold got me, but I guess I need to wait until this gets patched.

Also, I bought the coral claw that goes to this place from the woman in Winterhold, but the dungeon was never marked on my map for me. I ended up having to look the location up online.

EDIT: I did some more digging and it seems that this happens whenever you take a companion with you for some reason. I can't test that out until I get home, but I did have Lydia with me all of the times that I tried going in.

I had the very same problem, Everytime I went to enter yngol barrow The graphics flickered with bright colours and then everything went black. Eventually and after leaving Lydia at home I got into Yngol Barrow and got the treasure. However I was almost certain this was supposed to be a quest but the cave never showed up on my map untill I discovered its location and the woman in the shop no longer talks about it despite her originally asking me to report back with any findings. Furthermore the Claw has remained in my inventory whilst other claws dissapear when the puzzle doors open.

Yeah, I got it to work after I ditched Lydia as well. Glad I kept trying, it was a nice little dungeon. Besides the boss guy and a few traps, I thought it was nice relaxing change of pace for the game.

None of the claws have ever left my inventory. Weird. Are they supposed to? I just figured they were supposed to stick around as trophies or something.