My friends and I use Aternos occasionally for mods and survival but one friend can never connect. He says that whenever he tries to connect it loads and the message "Disconnected" appears. Just to clarify he cannot connect to any Aternos server but others can. We've tried the DynIP, older versions, we searched the web for a whole hour and a half, and even tried re installing Minecraft. We're planning on installing forge mods to the server as soon as we can resolve the issue.
That all being said, how do I fix the error of him not being able to join any Aternos server.