League of Legends Error 004: How to Fix the Patch Failure

League of Legends error 004 stops the client mid patch and blocks you from reaching the login screen. The error usually points to a local issue on your PC rather than a problem with Riot’s servers, and most players clear it without reinstalling the game.

What Causes League of Legends Error 004

The error appears when the client cannot finish downloading, verifying, or writing new patch files to your installation folder.

Low disk space on the drive where League of Legends is installed
The client launching without administrator permissions
Corrupted or leftover configuration files from a forced shutdown
Antivirus or firewall software blocking the patch process
An unstable internet connection dropping packets during download

How to Fix League of Legends Error 004

Work through these fixes in order, starting with the quickest checks before moving to the advanced fixes.

Fix 1: Run the Client as Administrator

Windows sometimes blocks the client from writing new files during a patch, and running it with elevated permissions clears this.

Close the League of Legends client completely.
Right-click the League of Legends icon on your desktop or in the install folder.
Select Properties, then open the Compatibility tab.
Check Run this program as an administrator.
Repeat the same steps for LeagueClient.exe and RiotClientServices.exe.
Relaunch the client and try patching again.

Fix 2: Free Up Disk Space

A patch that cannot fully extract because the drive is too full triggers error 004 on many setups.

Open This PC and check the free space on the drive with your League of Legends install.
Keep at least 20% of the drive free before patching.
Delete unused files, uninstall unused programs, or move large files to another drive.
Relaunch the client once you have freed up space.

Fix 3: Delete the game.cfg File

A corrupted configuration file left behind after a crash or forced shutdown can block new patches from applying.

Navigate to your Riot Games installation folder.
Open the Config folder inside the League of Legends directory.
Find game.cfg and delete it.
Restart the client. It regenerates the file automatically and applies the patch again.

Fix 4: Delete the RADS Release Folder

If deleting game.cfg does not clear the error, a leftover release folder inside RADS can still block the patch from applying cleanly.

Close the League of Legends client completely.
Navigate to your Riot Games installation folder.
Open RADS > projects > league_client > releases.
Delete the folder for the latest release version.
Restart the client and let it redownload that version on its own.

Fix 5: Run the Riot Repair Tool

Riot’s official repair utility, previously called the Hextech Repair Tool, scans the installation and fixes broken files without a full reinstall.

Open the Riot Client and go to Settings using the cog icon.
Select the General tab.
Click Initiate Full Repair.
Wait for the scan to finish, then relaunch League of Legends.

Fix 6: Check Your Antivirus Settings

Security software occasionally flags the patching process as suspicious and interrupts the download.

Open your antivirus program and check the quarantine or activity log for blocked files.
Add exceptions for LeagueClient.exe and RiotClientServices.exe.
If the issue continues, disable the antivirus temporarily and retry the patch.
Re-enable the antivirus once the patch completes.

Fix 7: Check Your Network Connection

Dropped packets during the patch download can corrupt the file mid transfer and trigger error 004, even when your disk space and permissions are fine.

Restart your modem and router by unplugging them for about 30 seconds.
Switch from Wi-Fi to a wired Ethernet connection while patching.
Pause other downloads or streaming that could be competing for bandwidth.
Retry the patch once your connection is stable.

Fix 8: Reinstall League of Legends

If the fixes above do not resolve error 004, a clean install clears any deeper file corruption.

Open Control Panel and go to Programs and Features.
Select League of Legends and click Uninstall.
Navigate to the installation folder and delete any remaining files.
Go to C:\Users[your username]\AppData\Local and delete the Riot Games folder if it still exists.
Download the client fresh from Riot’s website and install it.

Frequently Asked Questions

Is League of Legends error 004 a server side issue?

Most reports trace back to the local machine running the client, not Riot’s servers. Server side problems are rare and usually resolved on Riot’s end within a short window.

How long does a full repair take?

A Riot Repair Tool scan typically finishes within a few minutes. A full reinstall takes longer and depends mostly on your internet speed.

Why does error 004 keep coming back after every patch?

Recurring error 004 usually points to a failing drive, a persistent antivirus conflict, or a chronically unstable connection. Moving the install to a different drive or switching security software often stops the pattern.

League of Legends error 004 almost always comes down to a local issue on your PC, whether that’s disk space, admin permissions, a corrupted config file, or a shaky connection during the patch. Work through the fixes in order, and most players clear the error within the first few steps without ever needing a full reinstall. If it keeps coming back after every patch, check for a failing drive or a persistent antivirus conflict, since that’s usually the real root cause behind repeat errors.

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