The bug in which you cannot speak with either Ulfric or Galmar to continue the main quest line is not an uncommon one.
It's been brought up many MANY times on these forums and is all across the internet with people asking how to fix this.

When I encountered the bug my most recent save was about 42 hours of gameplay away from where I was so resetting just didn't seem like a good fix. So, being that I enjoy this game, I decided to tackle all of the other quests first and patiently wait for them to solve this bug in the next update.

I can honestly say that after 120 hours of gameplay I've completely all of the significant quest lines and am getting ever closer to level 50.
I find that they still haven't (it's been out a month now) fixed this common bug and are showing no signs of ever doing so. If it doesn't get fixed I'm just not going to buy any more Bethesda games because this is ridiculous... I used to make games and I know how non-difficult a bug like this can be to solve.

Apply for a job at Bethesda and offer to patch it then.