I've done some playing around with the console to try to set up the quest line to the point where the cave entrance is revieled ... but the NPC's don't open it, and just try to walk through the wall, and eventually do. I can use the console to turn off colision and walk through myself, turn it back on, then proceed through the doorway... but no matter what I do with trying to retrigger the cave entrance via the quest lines, it doesn't work.
I finished this quest a long time ago, so going back to an old save game isn't really an option. If anyone know how to fix it via the console please post a reply.
****************************************************************************************************************
edit: I went back through all my saved games and found the 2 savegames where the bug popped up. Saved game A works fine, Nightingale hall entrance works fine, while savegame B has the bugged entrance. Both savegames are only 6 minutes apart, so if Bethseda wants to take a look at my savegames to find out what causes it, let me know and I can email the 2 saves to you. Unfortunately for me, they are from almost a week ago, and I been playing pretty heavily the past week since I am off from work... So I can't really roll back to my old save game :[
