How to Fix 'Failed to Verify Username' on Your Minecraft Server

Diagnose and fix Failed to verify username errors on your Minecraft Java server — Mojang outage, online-mode mismatch, BungeeCord forwarding.

"Failed to verify username" means the server tried to confirm a player's account with Mojang's session servers and didn't get a valid response. It's almost always one of three things: a Mojang outage, an online-mode mismatch, or a misconfigured proxy (BungeeCord/Velocity).

Quick Diagnosis

What you see	Most likely cause
All players failing at the same time	Mojang session servers are down
Only one player failing	Their client / account / network issue
Failing only on a backend server behind a proxy	BungeeCord/Velocity forwarding broken
Failing right after enabling a proxy	Backend `online-mode` not set to false

Fix It

Check Mojang's status

Visit status.mojang.com or xitter.com. If the Sessions service is down, wait — there's nothing to fix on your end. This usually clears in 5–30 minutes.

Verify online-mode for your setup

Open server.properties and check online-mode:

Setup	online-mode
Standalone server (no proxy)	`true`
Backend server behind BungeeCord/Velocity proxy	`false`
Standalone "cracked" server (insecure)	`false`

If you have a proxy, the proxy handles authentication and the backend must have online-mode=false. Otherwise both the proxy and the backend will try to authenticate, and the second one fails.

Check BungeeCord/Velocity IP forwarding

Behind a proxy, the backend needs to trust the proxy's player info. This requires:

BungeeCord legacy mode: settings.yml → ip_forward: true and Spigot's bungeecord: true
Modern Velocity / Paper: Velocity secret key in Paper's paper-global.yml → proxies.velocity.secret

Without forwarding, the backend rejects connections from the proxy. See BungeeCord IP Forwarding.

For single-player issues, try client-side fixes

If only one player can't connect:

Restart their Minecraft launcher (not just the game)
Sign out and back into their Microsoft/Mojang account in the launcher
Try a different Minecraft profile to rule out a corrupted profile
Check their internet — failed handshakes can come from packet loss
Switch DNS to 1.1.1.1 or 8.8.8.8 to rule out their ISP DNS

How online-mode Works

Setting	What happens at login
`online-mode=true`	Server contacts `sessionserver.mojang.com` to verify the player owns their UUID
`online-mode=false`	Server skips verification — accepts any username

Security warning: online-mode=false allows cracked clients but also lets anyone connect with any username, including impersonating your admins. Only disable on private servers behind a whitelist or proxy.

Proxy Authentication Flow

When you have a BungeeCord/Velocity proxy:

Player → Proxy (online-mode=true, authenticates with Mojang)
         ↓
         Backend (online-mode=false, trusts proxy via IP forwarding)

If forwarding is broken, the backend doesn't trust the proxy and rejects the connection. Symptoms:

"Failed to verify username" on the backend
"If you wish to use IP forwarding, please enable it..." in proxy console
Backend log shows player connecting with random UUID

Common Mistakes

Mistake	Fix
Backend `online-mode=true` behind a proxy	Set to `false` on the backend
Proxy `online-mode=false`	Set to `true` on the proxy (Mojang verification happens here)
Forgetting to enable BungeeCord mode in `spigot.yml`	Set `bungeecord: true`
Velocity secret missing or mismatched	Copy the exact secret from `forwarding.secret` to `paper-global.yml`
Restarting only the backend after config change	Restart both proxy and backend

How to Fix 'Failed to Verify Username' on Your Minecraft Server

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