Okay, so out of curiosity, I've tried joining the old Mario Kart server on three different accounts on three different computers, and for some strange
reason, this error message pops up rather than downloading the map as usual on all 9 occasions of trying to join.
For what reason it is doing this I don't know, maybe something to do with my internet connection, but no fixes I've looked up have seemed to do anything, I also kinda doubt that since I have not had any problems downloading other custom maps through TF2 any time recently.
However when the rotation of map switches over to 2fort or some other stock Valve map (which I'm not really sure why it does that), everything works fine as usual.
Help would be appreciated.
--- Update ---
Update: Maybe the lack of people has something to do with the map DLing since even when the map switched to the Space map (which of the time of posting, currently is), I still received the missing map message.
This may also explain how the server is empty a large majority of the time when the actual MK maps are playing, and how it does receive traffic when other map (like 2fort) for some reason come on the rotation.
Also the reasoning I see for why a couple may be able to log on to the server recently is that they may have had the map prior to now (which is the case for the space map at least)