"A critical error has occurred and the process must be terminated."

I was playing on my PC earlier today, when the game stopped, and then it showed this message I put in the title. I have tried a couple of things to solve this problem, however, none proved to be successful. Those were:

- Reinstalled the game.

-Tried to open the app as administrator.

Fortunately, I was able to finish and win the game using my phone, but I really want to play on my computer.

That sounds awful.

I can't think of anything beyond standard protocol, namely:

1. Uninstall the game
2. Restart your computer
3. Reinstall

Beyond that, I'd try Riot support.  They can be a little slow to respond, but they are generally fairly helpful.