So I'm on one of the final quests "The Nuclear Option" , I fast travel to the institute and there r NO npcs in site and it immediately says I completed the quest, it will not let me fast travel out or use the elevator , my closest save takes me either right back into the institute, or back to lvl 27(im currently lvl 50), from what I've read the bug accursed if u fast travel there with power armor on which is what I did, plz help!!!