During the compiling of a Quake 4 MP map the following error may crop up;
WARNING : idCollisionModeManagerLocal::ChopWindingWithBrush: primitive [n] more than 128 windings
Where [n] is a number associated with the corrupted brush (primitive)Solution
This happens for a similar reason to when the error crops up during Quake 3 map compiles as explained here
As this error can happen with very large brushes try cutting large brushes into small segments.