Maps were taken out when shaders were added.There is no way to change the map anymore, you can change the environment (the ground texture, the skybox, the fog, etc) but that's about it
You could always try building it yourself.
What? WHAT!?!? THEY TOOK OUT ONE OF THE BEST GOD DAMN FEATURES IN THE GAME!?!?!
maps were some half-assed technology from 1996
We had to sacrifice maps for shaders (even though every game engine since 2003 has both)
I can't run shaders without getting like 10 fps.So I never gave a single stuff about the update.
Badspot also got around to stating the obvious