How to fix “A critical error has occurred” in League of Legends

Nicholas James

Nicholas James

“A critical error has occurred” stopping your LoL? Here’s how to fix it.

If you're running into the dauntingly-phrased "a critical error has occurred" in League of Legends, look no further. Here's how to fix the critical error bug in League of Legends.

If you're running into a system pop-up that says "A critical error has occurred, process terminated" while trying to launch or run the game, it's incredibly frustrating. League of Legends is known for its bugs, but this is one of the worst. The error message doesn't provide anything more specific, so it can be hard to find information to go on. Luckily for the already unlucky fans encountering this error, it's been narrowed down to a few issues.

How to fix "A critical error has occurred" League of Legends issue

The critical error code can pop up in a variety of situations. Some fans report it when first starting and launching the client, while others have had it consistently happen during games of League of Legends. The error will be accompanied by the League of Legends client and game process both crashing, and a system error message from your OS.

Image via Riot Games
Image via Riot Games

Whatever the circumstances for your error, try Riot Games' recommended solution. Riot says that this error most commonly comes from other programs with overlay features interfering with League of Legends' system. This is Riot's recommended solution for this error code.

  • Use Control+Alt+Delete to Open Task Manager, then end all processes that have overlay features (Discord, Steam, etc)
  • Go into your League of Legends folder, delete the "Config" and "Logs" folders before relaunching the client.

This solution only works for some, as is often the case with League of Legends bugs. This secondary solution also works for some players.

  • Find your League of Legends folder, and open the Games folder inside of it
  • Right-click League of Legends.exe, select Properties, then select Compatibilities
  • Choose the "Run this program as administrator" and "Disable fullscreen optimization" options
  • Click Apply, then do the same for the LeagueClient.exe file in your League of Legends folder

Other solutions are the same as many other League of Legends bugs, disabling firewalls or antivirus software from affecting the program, updating drivers, and using the built-in repair tool. Once you've worked your way through all those options, if you've got no luck, you're best off reinstalling the game entirely.