.Map :: MoHAA Mapping

I got an really weird large yellow triangle shape in my map which looks like a futurist force field ( best way to describe it) and its massive and i dont understand it. I also place a edge wall at the side of map and its removed ??? i try deleting it and replacing it no luck.

can any one help me get rid of this unsual yellow triangle thing??

and

stop my level wall disappering i can e-mail the files if needed

many thx DD FIVEBOY

ive seen that twice, and each time it was from too many brushes touching another one, eg:
a ladder with too many rungs. each horizontal rung has 4 verts on each end, and these touch the vertical bars. every vert touching another brush adds to its total vert count, even tho those verts arent on that brush. so you have to cut the vertical bars into smaller pieces.
so check that you dont have any very long rails or ladders. if you have any very long brushes with other brushes touching it, use the clipper to cut it into a few smaller brushes.
if you have even more brushes touching another one, then when you compile, only about 5% of the map appears ingame, and everything else is fog