I am currently having problems at Jefferson Memorial during the Waters of Life quest.
Ive been to Jefferson Memorial before this quest, so i have already killed all enemies inside. All supermutants.
But Dad still wont enter the god damned building, still only giving me the option to say "Its still not safe blah blah.."

The weird things is, i′ve already been to the Vault in Little Lamplight, where I met Fawkes, got kidnapped by the enclave thingys, and taken to Raven Rock. How I got in the Vault, I dont know, because as far as I can tell from google, you aren′t able to enter it before you′ve completed the Waters of Life quest.

In the rotunda in J.M, is standing some man on the otherside of a class door. I can′t open the door, and he′s just standing there. I think i′ve seen him before, when i got kidnapped, but i′m not sure.

How do i solve this and get Dad to go inside Jefferson Memorial?
Or is it just impossible, and is glitching so bad, that i have to start all over, and don′t go to Little Lamplight before the Waters of Life quest is completed?

I really DEEPLY hope you can help me with this!!!!!

Reload a save from before you ever did Little Lamplight. Theres two ways to get into it, and you either somehow got past the gate in Murder Pass, or unlocked the vault's back door, either way you shouldn't have been able to get through without cheats unless the game has glitched *that* badly.

Basically, you've somehow broken sequence, and it looks like the game is confused as to what to do now...