DAI: The Descent DLC crash during cinematic

Same here, got it before I installed my new drivers for windows10 AND after, cinematic plays, screen goes black w/ logo in corner and can hear combat playing but cant do anything. 

This also keeps happening to me when I try to open, I believe, the SECOND RUNE-WARDED GATE.

I pull the lever to open the gate, a short cinematic plays, then the screen goes to black - I see the little loading icon in the bottom corner and hear what sounds like my characters in battle (but maybe that's just for effect), no buttons work whatsoever, it just stays loading for, seemingly, ever.

I tried waiting it out as Aquinan suggested and it would eventually say "Your journey has ended" and then I had to try again. I did this a few times and suddenly (while I was alt+tabbed) it worked. Hope this works out for you as well!

Interestingly, I don't consider waiting around until it loads and your party is half dead as "solved". 

Me neither. Also, shortly after it had finally loaded, it crashed to Desktop - so yay, it loaded, but hey, game is still broken.

This happened to me too. Eventually I set my graphics right down low and it was fine. Had to wait till the end of an enormously long fight to put them back up again :-(

Set your graphics to low at the main menu before you load your latest save. Should load properly. it happened to me and I have to close it thru the task manager. When I start up the game and check the settings, all my custom key binds were reset and graphics is to auto.