on my map that i am working on the ground in most places dissapares but is still solid. i have no idea how this is working but thats the problem im getting is there anyone who knows how to fix this problem

alpha texture and caulk underneath?

no there is no calk or alpha texture underneath.. should there be?

at least the bottom of your skybox

so i have to put caulk on the bottom of the sky box and that should fix the ground from dissapearing

Looks like the replys in this thread are not helping you, so we need to find this problem.

Ok normally if a ground texture dissapears thats suggests it's a alpha texture, the confusing part is this would also render them non solid so you would fall though, you said it was still solid.

The only way i could see this happening is if the ground texture was left as 'caulk', have you tried any differnet textures?

Are you sure the player is not getting stuck in the patch? too know if are, it would appear as if you are sliding around. Also could the player be walking on a surface below the patch?

no, you should HAVE a skybox

but you can place a large brush underneath your map, to prevent players from falling off.

idk what you mean by "disappearing", screenshot please

Make sure your not using a decal texture as your floor/ground.