What do -
"WARNING: models/mapobjects/kmlamp_white.tga has empty alpha channel"
"WARNING: brush plane with no normal"
mean?. I get a lot of each message in the console of radiant when loading my map. [vwperview]
First is harmless. Just means it doesn't have an alpha channel, which it doesn't NEED to have. The second is potentially more annoying. You have a brush with a f*cked up face which wont be shown. Vertex manipulation of the brush is likely to make it disappear and become a phantom brush, if it isn't already one. Brush cleanup will fix these. Alternatively, it could be a patch which you have manually rotated (NOT A GOOD IDEA), which is nasty, as you probably won't be able to see it in editor, but will show up in game. I (djbob) enhanced brush cleanup to sort these too. However, I never seem to have patched the changes.
To get rid of it, look through the map using notepad. If you see any patches which have co-ordinates that have a decimal point, round them manually. [djbob]