I'm at the point in the main storyline where you attempt to get the two enemy sides to convene for peace on High Hrothgar. I've talked to Tulius, but upon talking to Ulfric he says "Galmar has given you a task, hasn't he? So go do it." This is because I accepted the quest to join the Stormcloaks and forgot about it until now. So I go kill the ice wraith and come back. Still doesn't work--Ulfric tells me to go talk to Galmar, and Galmar doesn't open a menu and says something like, "I don't know how you managed to convince Ulfric to talk with the Empire. It's all a big waste of time." I was like, "Oh, maybe it just completed somehow for me." I went to High Hrothgar but I can't start the peace conference because of this little thing.

Is there anything I can do to fix this?

Bump for necessity.

I got this as well, so do a few others. We can only hope Bethesda patch it. I've searched for hours, and there is no way around this.