Vanilla server unjoinable on 1.21.X: Failed

[ArmoredFuzzball]

I created a comment on this issue yesterday: PrismarineJS/node-minecraft-protocol#1289 (comment) suggesting an issue with the protocol and was told to try this on Flying-Squid. Well I just did, and the exact same problem is occuring at the exact same place in yggdrasil. I think the protocol really has an issue. Please let me know if I should open this over at NMP.

The client fails to connect with reason: Failed and the login event does not ever execute the callback:

import Squid from "flying-squid";

const options = {
    'motd': 'A Minecraft Server \nRunning flying-squid',
    'port': 25565,
    'max-players': 10,
    'online-mode': true,
    'logging': true,
    'gameMode': 1,
    'difficulty': 1,
    'worldFolder': 'world',
    'generation': {
        'name': 'diamond_square',
        'options': {
            'worldHeight': 80
        }
    },
    'kickTimeout': 10000,
    'plugins': {

    },
    'modpe': false,
    'view-distance': 10,
    'player-list-text': {
        'header': 'Flying squid',
        'footer': 'Test server'
    },
    'everybody-op': true,
    'max-entities': 100,
    'version': '1.21.1'
}

const server = Squid.createMCServer(options);

server.on("login", client => {
    //does not run
    console.log("join");
});

[extremeheat]

From the Discord earlier this month on 1.21.3.

Try a different machine and account

[ArmoredFuzzball]

I had my friend run the same code and attempt to join on their machine with their account (at a separate location). The exact same issue is occuring. The client reaches "Encrypting..." for a fraction of a second and then fails with "Failed". No other sign that anything is amiss.

This was tried on 1.21.1 and 1.21.3. The server does correctly display its motd and that it's online, but it cannot be connected to.

I mentioned in the comment on the other issue that this was occuring due to a node-fetch in Yggdrasil returning with no body.
This also seems to be the root of this issue: PrismarineJS/node-minecraft-protocol/issues/1340 because the client saying "Failed to verify username!" from back then is emitted from the same block of code that throws now (put console.error(err) at minecraft-protocol > src > server > login.js line 159 to see), but for some reason it no longer relays this message, it just says Failed instead.