max_map_brushes
 

So, a friend had this problem. he has 13372 brushes in his map (part of it is .ase). Is there a way to make this problem go away, without cutting down the detail of the map?

Well, the number of brushes isn't as big a problem as the number of leaf-nodes. In order to reduce the number (and compile time), be sure to use detail and hint brushes properly. Here's a good tutorial: Return to Castle Wolfenstein: nib's Mapper Resource Center

And if that doesn't work, try CSG merging brushes (ctrl U).

And turn off the autoclip option on all his models. The brush limit is over 32,000 but for each model triangle autoclipped an extra brush is added.