Right at the moment I chose ultra graphics it froze and then crashed. Before this I had lowered to medium because it was lagging during the whole Caer Ellis temple of the lost gods map. The lag seemed to stop after that so back in town I raised it and it crashed.
I got your "report bug and play at lower graphics" message. Then I retried, doing the same thing. Game froze after clicking ultra but this time I left it alone and after a few moments it unfroze and I can play on ultra without any lag or problems just as I have could throughout the game except for Caer Ellis for some reason.
I also play on Ultra. I'm wondering if this is at all related to the issue I have where certain graphical/Ui elements are broken. They broke a lot of things on PC for the sake of this console-focused patch. It's been what, 72 hours? No word or even acknowledgement...