If your problem sounds like this, you're in the right place:

  • Patching failed and we're not sure why. Please restart the client to try patching again. (Error code 004)
  • What does Error code 004 mean?
  • I can't enter my game because of Error code 004.

Resolution

Error Code 004 means League of Legends tripped over its own patch. This usually happens when Riot Client doesn't have the permissions, storage space, or network access it needs to download and install the update. Let's try the steps below in order. 

  1. Restart the Riot Client. Fully close Riot Client, including from the system tray, then reopen it and try patching again.
  2. Restart your PC. A fresh restart can clear temporary issues, release locked files, and complete any pending Windows updates before League of Legends tries to patch again.
  3. Run the Riot Client as administrator. Windows permissions can sometimes get between Riot Client, your game, and Vanguard. Run the Riot Client with administrator permissions, then try launching your game again.
  4. Check your available storage space. Make sure the drive where the game is installed has enough free space to download and install the update. Clear some space if the drive is nearly full, then restart Riot Client.
  5. Configure your firewall. Your firewall may be blocking the Riot Client from communicating with our servers. Follow our guide to configure your firewall.
  6. Check your connection. If you made it this far, it’s time to bust out the big guns. Follow our PC Connection Troubleshooting Guide for step-by-step instructions on tackling potential connection issues.
  7. Reinstall your game. This can replace corrupted or missing game files that may be preventing Vanguard or your game from launching correctly. Follow our guide to uninstall and reinstall your game.

Still having issues?

If you still see the error after trying these steps, submit a ticket to Player Support. Make sure you attach your logs so we can take a closer look and help get you back in the game.