When I start my map me and others get the following error message in game:
"Display doesn't support downloadable gam"
(gam is not a typo. The message is that way)
This happens with steam, also as with older non steam version of ns.
Anyone knows something about that message? because I'm pretty lost here with that message

Though the map is playable quite normal, even with that message, I would be happy to remove the error.

Found the problem

my env_gamma was set to 2.7 instead of 1.7 by accident.
The error message appears when the value of env_gamma goes below 1.0 or above 2.0