there are a few ways of easly finding leaks.
1: create giant boxes covering portions of the map, and compile while having little portions uncovered with the box. Then, compile adn see if you get a leak error. If you do, you know the leak is in that little area. You can repeat this.
2: Create a box around your whole map, big, and make it hollow. Create a light_Environment in there and make it super bright. Use a silly color that is recognizable, like a gross light green. then, compile and walk around til you see the green leaking into your map. That would be were the leak is.