the red line shows you one (there might be even more) way from inside your map out into the void, and it ought to go through the leak, like gaps, cracks, holes. When found, close the leak and compile again until no leak is left.
If you are using detail brushes (which is recommended) turn on the detail filter (ctrl+d) to hide them while you are searching the hole, because only structural brushes can seal the map.
I have a skybox ect ect . but I think Moharadiant is winning this from me
Sorry to bother you but I think i'm leaving , because it's to diffecult for me now , I have spent hours and hours on a Frysian Farm ( Head , throth Body , that how we call this farm ). But now my map won't load even more , I can skry about this ...
Can they not make mohaaradiant better ,Like electrocad if you make a mistake in your drawing program he's giving a hint ?
Ok Wacko maybe a littl bit late but my sky box is now sealed with a structural box and indeed my LOD terrain doesn't seal it so another brush underneath it and whala