Sebastian is missing at the start of Repentance

Okay, I managed to get Exiled Prince running, and got through Duty in Act 1 just fine, but when I go to the Chantry to pick up Sebastian for his next quest, he just ISN'T THERE. You can hear Elthina talking to him and berating him for his sin, but she seems to be talking to thin air. The map points out where to find him to pick up the quest, but no Sebastian. I understand this DLC has lots of bugs, but I've never heard this one mentioned before. Is it reparable?