I've decided to finally undertake the Dawnguard DLC quests on the Xbox 360 (I'm level 241). I have the first quest to talk to the leader of the dawnguard, and when I activate it (only quest activated, even deactivated misc. quests) my compass directs me north from Riften, and when i checked the world map to see where and fast travel close by, it directs me southeast of the Nightengale Hall. I went to the mark on the map, and no one was there. I continued towards where the map says Fort Dawnguard is, yet when I got within sight of an overpass (like the guardpost on the southern edge of Riverwood) a message popped up in the top left corner of the screen saying I can't go this way and I could progress no further. My only bounty is 80 septim in Hjalmarch, and I'm confused as to why I can't go on or why the map and compass are disagreeing. Any help would be greatly appreciated.