Fix League of Legends 'A Critical Error Has Occurred' (Crash)

Updated: 11/29/2025

You are loading into Summoner's Rift, the champion portraits are at 100%, and suddenly the game closes. A cryptic Windows message appears: 'A critical error has occurred and the process must be terminated.' This is the worst nightmare for any ranked player because the game is still going on without you, and you are about to get hit with a LeaverBuster penalty. This error is usually caused by a corrupted config file or a conflict with third-party overlays like Blitz.gg or Discord.

Method 1: Delete the Config & Logs Folder

Old configuration settings often conflict with new patches. Forcing the game to generate fresh settings is the fastest fix.

Step 1: Navigate to Riot Games

Open File Explorer and go to:

Step 2: Delete Folders

Find the folders named Config and Logs. Select them both and delete them. Don't worry—your account level and skins are saved on the server. This only resets your video/audio settings.

Step 3: Launch a Custom Game

Launch the client and start a Custom Game to verify the fix. Do not jump straight into Ranked.

Method 2: Disable Overlays and Game Bar

League's anti-cheat system hates it when other apps draw over the screen.

• Discord: Go to User Settings > Game Overlay > Toggle 'Enable in-game overlay' to OFF.
• NVIDIA: Open GeForce Experience > Settings > General > Turn off 'In-Game Overlay'.
• Windows: Go to Settings > Gaming > Xbox Game Bar > Toggle OFF.

Method 3: The Hextech Repair Tool

If the crash persists, use Riot's official debugger.

Download the Hextech Repair Tool from the Riot Support site. Run it as Administrator, check the box for 'Force Repatch', and click Start. This will scan every game file for corruption.