So the last main quest I did was "Council Of The Five Companions". I was about level 40, talked to everyone in the Harborage, Varen opened a portal to Cold Harbour, or wherever he decides to send me to defeat Molag Bal. I decided I'd do some other things for a while and left.
Fast forward a couple days, I'm level 45, and decided to get back to it only to discover the quest has vanished from my journal and when I go back to Harborage the portal isn't there either. When I talk to everyone there they talk like the quest is still happenning. Varen keeps trolling me by saying "We're all counting on you Vestige", but refuses to open the portal.
Now, I've heard some people say that main story quests unlock every five levels. I never noticed this when playing previous story quests but I am certain that the quest and portal where there, and now they are not. I also just recieved the "Message Across Tamriel" quest which mentions Vanus Galerion's "plan to stop Molag Bal's incursion of Tamriel". I haven't started it yet because I'm afraid of progressing and messing anything up any further, but I'm not sure if this is anything to do with the final main quest "The God Of Schemes".
I haven't gone to support yet, just want to gather some more information from other players before I do, or see if someone can help.