Hey,
I'm currently v5 and stuck at skuldafn quest line, it being the last area I need to complete in order to advance to daggerfall.
My problem is that I completed the last quest first, songs of sovngarde, though a share quest, and the area does not show up as completed, not on my map, not in my journal. I tried getting the prequests though a share aswell, since I was not able to get them normally. But the npc - thane mera stormcloak, I need to talk to in skuldafn, is not there, since the whole area of skuldafn - act as though I already killed fildgur. I also tried teleporting to someone who was in the stage at skuldafn where the fighting was still going on, and he had yet to kill fildgur, in that case, I did not get into that instance of skuldafn, but the one where the fight is over.
I'm really stuck here, and out of options, support could not help me.
Looking for some feedback, if any have the same problem - and telling you not to do the last quest before the prequests, because unfortunately nothing can be done at this point.