Fix "Failed to login: Invalid session" in Minecraft
Invalid session is an account problem, not a server problem. Restarting the launcher fixes it most of the time, and here is what to do when it does not.
6 min read · Updated Oct 21, 2026 · By GuavaHost Team
The messages all mean the same thing:
Failed to login: Invalid session (Try restarting your game and the launcher)
Failed to login: The authentication servers are currently not reachable
Failed to login: Invalid session (Please restart your game)
When a player joins a Minecraft Java server, the server asks Microsoft's authentication service to confirm that this account really is who it says it is. A session token proves it. Invalid session means that token was missing, stale or rejected. Your server behaved correctly by refusing the join.
That is why nothing in your panel will fix this for the player. Everything below is on their side, apart from the last section.
The fixes, in the order that works
Work down the list. Most people stop at step two.
- Fully close Minecraft and the launcher. Not just the game window, the launcher as well. Then start both again. The launcher refreshes the token on startup, and a token that went stale while the game sat open for six hours comes back valid.
- Sign out and back in. In the launcher, open the account menu, sign out of the Microsoft account, then sign in again. This forces a completely new token instead of refreshing an old one.
- Check for a Microsoft or Mojang outage. If a whole group gets it at the same moment and nobody changed anything, this is usually why. There is nothing to do but wait, and it is normally minutes rather than hours.
- Check the system clock. A clock that is wrong by more than a few minutes breaks token validation. Turning on automatic time and time zone fixes it.
- Restart the computer. Worth doing before anything exotic, because it clears a stuck launcher process that is holding an old session.
- Reinstall the launcher. Last resort, and it rarely helps, but a corrupted launcher profile does occasionally cause this.
If the player is using a third party launcher for a modpack, have them check that it is signed in with the real Microsoft account and up to date. Older launcher builds broke when Microsoft changed its login flow, and some of them still ship with the old path.
When it is one player and nobody else
Check that they actually own Minecraft Java Edition. A player who owns Bedrock on an Xbox does not own Java, and a Java server will not take them. That sounds obvious, but it is a surprisingly common reason for a single person failing to join a server everyone else is on.
Two accounts on one computer also causes it: a launcher signed into a second profile, or a family member's account left signed in. Signing out and in with the right account clears it.
The server side: online-mode
There is one setting on your side that interacts with all of this, and it is worth understanding properly rather than toggling.
In server.properties on the Files tab:
online-mode=true
With online-mode=true, your server verifies every joining player with Microsoft. This is the default and it is what you want.
With online-mode=false, your server stops checking. It accepts any client that claims any username.
People find that second option while searching for this error, because it does make "Invalid session" go away. Here is what it actually costs you:
- Anyone can join as anyone. A stranger can type your username, walk in with your inventory, your permissions and your rank, and there is nothing your server can do to tell the difference. This is not a theoretical risk, it is the first thing that happens to an offline-mode server that gets found.
- Player data is keyed on names, not accounts. Rename yourself and you are a new player. Someone else takes your old name and they inherit your data.
- Permissions become meaningless. Any permissions plugin is giving ranks to a claimed name, not a verified account.
- Most paid plugin and anti-cheat protections weaken, because they cannot trust identity.
The only legitimate reasons to turn it off are a server sitting behind a proxy, which does the authentication itself, or a private LAN-style setup nobody outside can reach. For a proxy network, the backend servers run with online-mode=false and the proxy handles verification, and the backends must be unreachable from the outside. Run a Minecraft network with Velocity or BungeeCord covers how that fits together.
Changing this value needs a restart, and the file itself is explained in Editing server.properties.
If your goal is to let Bedrock players in
This is the real reason most people go looking for offline mode, and there is a proper answer for it.
Bedrock players on Windows, Xbox, PlayStation, Switch and phones do not have Java accounts, so they cannot authenticate against a Java server. The right tool is Geyser with Floodgate: Geyser translates between the two editions, and Floodgate lets a verified Bedrock account join your Java server without a Java account and without turning off online-mode.
That keeps your Java players verified, keeps your permissions meaningful, and lets Bedrock players in through a supported path. Start with Geyser explained for what does and does not carry across, then Set up Geyser and Floodgate for the install. The port Bedrock players use is the single most common thing to get wrong, and The Bedrock port on a Geyser server covers it.
Cracked clients are the other thing people ask about. A cracked client cannot pass authentication, so it only works on an offline-mode server, with all the identity problems above. We do not recommend building a community on one.
What this error is not
- It is not your RAM, your plan or your location.
- It is not a plugin. Plugins do not get a say in whether authentication passes.
- It is not your world or your backups.
- It is not fixed by reinstalling the server.
If you catch yourself about to reinstall over this, stop. Have the player restart their launcher first.
Common questions
Why does Invalid session happen when my server is fine?
Because the error happens between the player's launcher and Microsoft's authentication service, before your server has any part in it. Your server only sees that the verification failed and refuses the join, which is exactly what it should do.
Should I set online-mode to false to fix this?
No, unless your server sits behind a proxy that authenticates players for you. Turning it off lets anyone join claiming any username, which hands over inventories, ranks and permissions to whoever types the right name first.
How do I let Bedrock players join without turning off online-mode?
Install Geyser together with Floodgate. Geyser translates the Bedrock protocol into Java, and Floodgate lets a verified Bedrock account in without needing a Java account, so your Java players stay properly authenticated.
Everyone in my group got this at once. Is that still their launcher?
Probably not. When a whole group fails at the same moment with nothing changed, it is usually a Microsoft authentication outage. Wait a few minutes and try again before changing any settings.
Still stuck? Jump into our Discord at discord.gg/GuavaHost and the team will help you out.
- minecraft
- java
- login
- authentication
- troubleshooting
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