The campaign's control.luas use things like game.player and game.show_message_dialog, which are single player only. Was the error people were getting when joining something like "this can only be used when map contains exactly one player"? Might work if you replace the control.lua in the ...

Hello, I noticed it is not possible to play multiplayer in Campaign mode. I have done the following: I played campaign on single player, I saved the gameplay, then I started a new multiplayer game and loaded the save game from the campaign and it worked for me, but no other player could join. Is it ...