Yet another bug on the massive pile of fail and spaghetti code.
I've found a solution to this bug. First, get the "How Little We Know" quest from the Yes Man or elsewhere. Next, make sure that is selected as your active quest in your Pip-Boy. Then go into the console by pressing ` then enter movetoqt. You will warp into gommorah without the bugged weapon check occurring. This is slightly cheating since you can avoid disarmament inside the building, but whatever.
