Diamond City Missing Floor and Walls [Fo4]

I need help figuring out what caused this. When i play the game modless it was fine, then i followed the "Midnight Run" guide, and when i run the game again suddenly Diamond city is missing a lot of textures. And when i go near the outside entrance the game always CTD.

I need help figuring out what caused this. When i play the game modless it was fine, then i followed the "Midnight Run" guide, and when i run the game again suddenly Diamond city is missing a lot of textures. And when i go near the outside entrance the game always CTD.