Basically I did the nuclear option mission for the brotherhood and did the whole first part where I go through the "old robotics " lab and end up in the biology lab once you clear all the enemies your in the main part of the institute your supposed to go down an elevator and I did but it went staight down stopped for a second the doors didn't open and it went straight back up and the door opened were it opened was the very top floor were you began so I went all the way back down and the elevator wasn't there the button said elevator acces denied so I traveled around to see if I was jut doing something wrong I gave up after a while and looked at a walk through they went dow. The elevator at that moment I thought I thought to just fast travel out I can't then I thought to crawl back out of the whole I came from didn't work so I just turned the game off and that's how I ended up here (and I don't have another save that's even close to this point ) so until I there's a patch or someone knows a solution I sure can't find one I can't play a save that I have over 40 hours in