I have made a basic 'room' map, just so I can do some interesting things with it, like light it. However I came across a 'problem' which is probably down to me being a fail mapping newbie.
I had a light half within a brush, so I could have directional lighting (see first attachment), but when I dev-mapped it with the light on 200 this happened (second attachment).
Now when building my map I got the following error, which is likely to have been part of the problem:
Entity 1, Brush 0: Entity leaked
However, my lights don't actually leak from the map (first attachment again). Any ideas?
*Edit: meh, going to get better view of the plan, but you should be able to get the jist from the graphical.