I have recently noticed that whenever the vote goes to the map ttt_mc_67thway, the server goes from about 15 people to about 5. The next time the majority of people voted for this map, I had an error saying that I do not have the map and that it will disconnect me from the server. After a while, I figured out how to fix it. To fix it you need to go to the Garry's Mod workshop and search "ttt_mc_67thway" then subscribe to the map. After you have done this, restart Garry's Mod and try reconnect. This fix worked for me and I hope it will work for all of you having this error as well.
Clever and direct thinking! I have had this error too when the map was first added. Although, the problem for me was that the FastDL didn't download the map automatically and probably didn't check to see if the player had the map "ttt_mc_67thway", so the loader prompted a message saying "You don't have the map 'ttt_mc_67thway'" or something along the lines of that. The problem seems to persist for about two minutes when I try to reconnect during that time frame. After, the loader seems to realize the player does not have the map and downloads it promptly. It seems to no longer happen after that since the map is downloaded into your custom files at that point and you aren't missing it. This is just a possible alternative which may have come to some people seamlessly without realizing it. Nonetheless, your solution prevents the problem from happening in the first place and possibly for future maps too so good job!
