this problem with the co-op has existed for at least six months.
people usually ask in faf chat or discord, where these questions are criticized by people who have everything working.
as a result, it's easier not to play co-op than to look for a solution and listen that you're the only loser who doesn't have something working.
the lobby is starting. the chat lobby writes:
"player" map is missing.
maps/x1ca_coop_001/x1ca_coop_001_scenario.lua.
the selected map dose not exist
the game does not allow the launch
if you check for files, everything is downloaded, a folder with many text files and one picture.
the analysis of configs does not give hints of a solution. all links are correct. there is no log file without the ability to start the game.
of a popular solution for non-English-speaking operating systems with the removal of everything not related to English in the links does not help.
the second popular solution to problems with removing mods does not help
the third popular solution some have tried "extreme" with reinstalling the game / client/ OS does not help.
it is not possible to formulate the problem properly on the forum, there is little information. different people describe the situation differently.