I installed the steam version of the game and downloaded the celeste fan project gui, did all steps but when i try to play, clicking play online the game send me the message "Celeste Fan Project already running", anyone knows how to solve it?
I assume it was already running ?
Not sure why if it wasnt, but in the launcher, you can set it to start using steam to launch it, in Tools > Helpers > Steam
Did you look in Taskmanager to see if it was running ? if so you can use that to close it
I also had this problem so I began using the spartan.exe launcher option where you include your email address and password in the "Target" field. As long as I turn off the antivirus monitor, it works well.