Invisible Walls

[AfterDeath]

I've been working on my map for a couple weeks now. All of sudden, some of my walls have turned invisible after I added a bunch of things to the map. They all have "wall" textures (not invisible texture) and show up properly on MoHRadiant, but not on MoHAA.

I have tried copying walls that show up properly and replacing the "defective" ones, but they the same wall is still invisible. This also happens to parts of two ladders that I have on my map. Most of the invisible walls are near each other.

Any ideas??

[tltrude]

Rotating a copy can cause faces to not show up in the game. Try Selection > Snap Points to Grid. Or, Make the wall one unit larger. Deleting and remaking the wall from scratch might work too, but if the bad face is on a vis boundry, redoing it may not help.

[M&M]

u might have made these walls detail and filtered them accidently .
try turning the filters off .and if they were of ,try turning them on then off again .

some brushes look in radient like they arent detail while they are .and when u filter them they disappear