League of Legends Vanguard Has Encountered an Error: How to Fix It

Easy 10-30 minutes Medium Severity Verified June 2026
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Error Code
Vanguard Has Encountered an Error
Brand
League of Legends
Product Type
game
Severity
Medium
DIY Difficulty
Easy
Estimated Fix Time
10-30 minutes
The 'Vanguard Has Encountered an Error' message in League of Legends occurs when Riot's anti-cheat system experiences a fault or conflict with your system. This error typically prevents you from launching the game and requires specific troubleshooting steps to resolve.
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Tools You'll Need

How to Fix Error Code Vanguard Has Encountered an Error

  1. Restart Your Computer

    Save any open work before restarting your computer

  2. Run League of Legends as Administrator

  3. Update Windows and Drivers

  4. Disable Conflicting Security Software Temporarily

    Only disable security software temporarily and ensure you re-enable it after testing

  5. Reinstall Riot Vanguard

  6. Check for Virtualization Conflicts

    Disabling virtualization features may affect other software that depends on them

  7. Verify Game Files

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When to Call a Professional

Contact Riot Support if the error persists after trying all steps, especially if you're experiencing hardware compatibility issues or need help with advanced BIOS settings.

Frequently Asked Questions

Why does Vanguard keep giving me errors?
Vanguard errors typically occur due to conflicts with other software, outdated drivers, or system-level issues. The anti-cheat system requires specific permissions and can conflict with virtualization software, some antivirus programs, or corrupted system files.
Can I play League of Legends without Vanguard?
No, Riot Vanguard is required to play League of Legends. The anti-cheat system must be running for the game to launch. You cannot bypass or disable Vanguard while playing.
Does Vanguard affect my computer's performance?
Vanguard runs at the kernel level and may cause minor performance impacts on some systems. It's designed to be lightweight, but older computers or those with limited resources might experience slight performance decreases.
Is it safe to run League of Legends as administrator?
Yes, running League of Legends as administrator is safe and often necessary for Vanguard to function properly. This gives the anti-cheat system the permissions it needs to monitor for cheating software.
How do I completely remove and reinstall Vanguard?
Uninstall Riot Vanguard through Windows Settings > Apps, restart your computer, then launch League of Legends. The game will automatically download and install a fresh copy of Vanguard during startup.

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