When I interact with the Arcaneum Vendor, I click "Can we see your wares" dialog option, the screen goes dark for a second, but returns to the party view. The video gets choppy, and I'm unable to move my characters. If I mouse over the screen where things should be, I do see the tooltop for items, but I can not see them. When I hit the ESC key, I briefly see the open wares windows before fading to the normal UI.
EDIT: Upon reloading the game, the vendor is working again.
This has occurred with every vendor in game. The screen goes black and does not progress to the vendor sell/buy screen. Once it happens the it requires you load a previous save to fix. It will not happen every time--but once it happens all vendors are impacted. It took me 40 minutes of loading previous files to complete all of my purchases. 👎