I have been getting this error since starting to make the server last sunday, have confirmed that ports are opened, it's on a linux so no firewall enabled, it's IP-Passthroughed so the router firewall has no affect on it. Me and my friends all get the same error. I see their names in my server console when they try to join. Please help!
Well that means the you can connect to the Auth servers. So the problem must be with your server. If it’s just your friends who play you could put the server in offline mode
