I keep finding areas of missing terrain which if I walk onto I just fall until I land in a giant square of water under the map. I've seen this in Oblivion but it usually resolves itself if you exit the game and load it again, but this does not fix these areas I've found in Fallout 3. I've found one just south of Raven Rock, and I found another while out in the wastes but I forget where, and now I've just found one while trying to get into the DC area just next to the Red Racer Factory.

I've turned all my mods off (I don't even use very many) and it still happens, but it is very annoying as I can't reach some areas of the game because of the big impassable holes in the ground. http://i13.photobucket.com/albums/a288/sinderelly/Fallout/fallout3_missingterrain.jpg. You can still see the distant lod terrain in the hole, but if I walk forward I will fall straight through that into a giant gray box with water that is impossible to get out of. I just ignored the first two that I found because while inconvenient they were mostly in the middle of nowhere, however this one is completely preventing me from reaching that door you can see floating there.

If anyone knows how I can resolve this I would appreciate it, thank you.

If you are using texture mods, I would disable those. It looks like the area is not loading correctly though. May have to uninstall the game, making sure to remove all add-ons from Fallout 3 directory and Fallout.INI file from Documents. Then I would reinstall the game.

I don't have any texture mods other than ones that replace the texture of Reilly's Rangers armor and I can't really see how that would affect it.

I've tried it with all my other mods turned off and it still happens, I haven't tried reinstalling but I guess I could try it if there isn't anything else to do.

I think I figured out what my problem was, I had cleaned the official DLC with FO3Edit as I had done in Oblivion, but I tried reverting to the original DLC .esms and now it all seems to be fixed. I guess I caused the problem myself heh, oops.