League of Legends Error Code 004: How to Fix It

Easy 30-90 minutes Medium Severity Verified June 2026
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Error Code
Error Code 004
Brand
League of Legends
Product Type
game
Severity
Medium
DIY Difficulty
Easy
Estimated Fix Time
30-90 minutes
League of Legends Error Code 004 occurs when the game client has corrupted files that prevent it from starting properly. This error typically appears during game launch and can be caused by incomplete downloads, antivirus interference, or file corruption during updates.
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Tools You'll Need

How to Fix Error Code Error Code 004

  1. Restart Riot Client and Computer

  2. Run League of Legends as Administrator

  3. Use Hextech Repair Tool

  4. Disable Antivirus Temporarily

    Remember to re-enable your antivirus protection after testing. Only download the repair tool from official Riot Games sources.

  5. Clear League of Legends Cache

    Back up your game settings before deleting these files, as you'll need to reconfigure your in-game options.

  6. Perform Clean Reinstall

    This will delete all your game settings and you'll need to download the entire game again, which may take several hours depending on your internet connection.
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When to Call a Professional

If you continue experiencing Error Code 004 after trying all steps, contact Riot Games Support directly. They can provide account-specific troubleshooting and may need to reset certain account flags that could be causing persistent file corruption issues.

Frequently Asked Questions

What causes League of Legends Error Code 004?
Error Code 004 is caused by corrupted game client files, often due to incomplete updates, antivirus interference, network interruptions during downloads, or system crashes during gameplay.
Will I lose my game progress if I reinstall League of Legends?
No, your account progress, champions, skins, and rank are stored on Riot's servers. Only local settings like keybinds and graphics options will be reset when you reinstall.
How long does the Hextech Repair Tool take to fix corrupted files?
The Hextech Repair Tool typically takes 15-45 minutes depending on how many files need to be redownloaded and your internet speed. The Force Repatch option may take longer as it verifies all game files.
Can Error Code 004 be prevented?
Yes, you can prevent this error by ensuring stable internet during updates, adding League of Legends to antivirus exclusions, and avoiding force-closing the game during patches or file verification processes.

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