As the title, it's missing, just a large hole in the map. One that you fall into the world and cannot get out of. This is my 2nd time i have ran across the robot repair center not being there. Any ideas on what is causing this? (or a fix?)

The area is failing to load.
I have seen it a few times in various places in Fallout 3 and in New Vegas.

I saved as I had not fallen in, exited the game, then went back in and it was better.

If it is always this one place, check over any mods which impact it, if any.