So since I recently reinstalled tf2 I only had the standard maps. So when I joined a lobby that played cp_process_final, I made sure to download the map from the link given in the lobby (and of course placed it in the maps folder).
But when everyone was ready, and I started to connect to the server, I saw that he tried to download the map and then I got an error saying "Client map differs from the servers". I tried reinstalling the map, I tried removing it from my folder and letting it download from the server, but nothing worked.
So now my reliability is pretty fucked up due to a very low amount of games, but I hope that doesn't matter too much. Anyways, I'd like to know if there is a solution, because else I can only join the badlands/granary/... and be sure of playing.