In the Dragon Rising quest, after I killed Mirmulniir nothing happens. His body won't burn up and Irileth and the guards are just standing in one place with no dialogue when I interact with them. I went and explored and did other activities for a few in game days but even when I came back things were just frozen in one place.

Can someone please help? I've done this quest at least 5 times before on other characters, not sure why it broke on my newest.