Fix "Failed to verify username" on a Minecraft server

In the Console you see the refused join as a line like Username 'Steve' tried to join with an invalid session. That tells you the server did the check and the service said no.

1. Close Minecraft completely, and close the Minecraft Launcher too.
2. Open the launcher again. If it asks you to sign in, do so with the Microsoft account that owns the game.
3. Start the game and join again.
4. Still refused? In the launcher, sign out of the account, sign in again and try once more.
5. Turn off any VPN or proxy program and try again.
6. Check that you can join another online server. If you cannot join any, the problem is with your account or the login service, not with this server.

A game that stayed open for many hours, or a computer that came back from sleep, often has a stale session. Restarting the launcher gets a fresh one.

The game can show its own version of this problem before the server is even reached: Failed to log in: Invalid session (Try restarting your game and the launcher). The fix is the same: restart both.

When all players are refused at the same time, the cause is almost never their accounts. Check these in order:

1. Look at the Console when someone tries to join. Authentication servers are down. Please try again later, sorry! means the server could not reach the login service at all.
2. Ask a player to try another well-known online server. If that fails too, the login service has an outage. It is usually fixed within the hour, and there is nothing to change on your side.
3. If other servers work and yours does not, check Block proxy connections and, on a network, the forwarding setup, both below.

During an outage, players who were already online can usually keep playing. Only new joins are refused.

The Block proxy connections setting in Settings, under Access, is prevent-proxy-connections in server.properties. With it on, the server also sends the player's network address to the login service. When the address the server sees is not the address the player signed in from, the service says no, and the player gets "Failed to verify username".

• A player on a VPN, or on a network that switches addresses, is refused.
• If many players are refused after you turned it on, turn it off, press Save changes and restart.

Block proxy connections is off by default. For a whitelisted server it adds little; whitelist and operators keeps strangers out more reliably.

On a server network, the Velocity proxy checks the account, not the servers behind it. It then passes the verified player on to each server with a shared secret. For that to work:

When players are refused only on a network, the forwarding on one of the servers usually no longer matches the proxy. In Settings, click Take the network apart on the Network card, then pick the servers again under Server network and click Build the network. The panel writes the settings fresh.

Vanilla servers cannot use modern forwarding, and Fabric needs an extra mod for it. The panel builds networks from Paper and Purpur servers.

Turning off Verify accounts with Mojang, which is online-mode=false, makes the message go away, because the server stops checking. It also opens the server to anyone:

The panel warns about this next to the switch. The only safe use of online mode off is behind a proxy that checks accounts itself, as on a network the panel built. For other ways to keep your server safe, see stop griefing.