Quick Summary
"Failed to login: Invalid session" in Minecraft means that your game client's current session ID doesn't match what the Minecraft server expects. This usually happens when there's a problem verifying your login with Mojang's servers or if too much time has passed since you last logged in.
Common Causes
- Session Timeout: Minecraft sessions are not indefinite. If the game client is left open for a long time, the session can expire, leading to this error when you try to rejoin a server.
- Launcher Issues: Problems with the Minecraft Launcher, such as outdated versions or corrupted files, can prevent proper session verification.
- Multiple Minecraft Instances: Running multiple instances of Minecraft with the same account simultaneously can cause session conflicts.
- Internet Connection Problems: Unstable or interrupted internet connections can interfere with the login process and session validation.
- Server Issues: In rare cases, problems on the Minecraft server itself can cause it to misinterpret your session ID.
Step-by-Step Fixes
Method 1: Restart Minecraft and the Launcher Show Steps ↓
Step 1: Close both the Minecraft game and the Minecraft Launcher completely.
Step 2: Reopen the Minecraft Launcher.
Step 3: Log in again if prompted.
Step 4: Launch Minecraft and try joining the server.
Method 2: Restart Your Computer Show Steps ↓
Step 1: Save any important work and close all programs.
Step 2: Restart your computer.
Step 3: After restarting, launch the Minecraft Launcher and Minecraft again to see if the issue is resolved.
Method 3: Check Your Internet Connection Show Steps ↓
Step 1: Ensure you have a stable internet connection. Try browsing the web or running a speed test.
Step 2: If you are using Wi-Fi, try switching to a wired connection (Ethernet) if possible.
Step 3: Restart your modem and router.
Method 4: Check Minecraft's Servers Status Show Steps ↓
Step 1: Go to the Mojang status page (usually status.mojang.com or a similar site that is easy to find via web search).
Step 2: Check if there are any reported problems with the authentication servers.
Step 3: If there are server issues, wait for them to be resolved by Mojang before trying to log in again.
Method 5: Delete Minecraft Authentication File Show Steps ↓
Step 1: Close Minecraft and the Minecraft Launcher.
Step 2: Navigate to your .minecraft folder (usually located in %appdata% on Windows).
Step 3: Delete the launcher_profiles.json file. This file stores your authentication data.
Step 4: Reopen the Minecraft Launcher and log in again. This will create a new authentication file.
Method 6: Reinstall the Minecraft Launcher Show Steps ↓
Step 1: Uninstall the Minecraft Launcher from your computer.
Step 2: Download the latest version of the Minecraft Launcher from the official Minecraft website (minecraft.net).
Step 3: Install the new launcher and log in with your Mojang/Microsoft account.