What type of level are you working in? additive or subtractive? Subtract will only work if you are working in a subtractive level or are trying to subtract from an additive brush.
hey guys I have problem with CSG subtract option. When i press the CSG add button its working properly, but when i try the subtract, nothing happens I have this problem since i started using UDK. Is there any solution for this problem?
also if you have a CSG subtract brush that is the same size of a CSG add brush, it will either do nothing, or completely disappear. a friend of mine had a level that i went through to clean up, and 1 area had about 8 CSG add/subtract brushes on top of 1 another, but the add still showed over them all.