Fallen

Run steam from the terminal then run your game, when you get the error exit steam, the terminal might give us an exact error, or at least where the problem...

Have you modifed the config file? If so, rename your config file to MangoHud.cong.example, download the default config file from the github repository and place it where your old config...

And does this error persist with other text editors? Try using vim or nano.

lmao, I'm out of ideas, at least it doesn't seem to be anything major.

Which WINE version are you using? For league of legends it should be WIne-GE-Proton8-27-LoL, you can find this in the wine manager tabs under Downloads.

I seem to have found another post with a similiar error, https://github.com/Heroic-Games-Launcher/HeroicGamesLauncher/issues/2701, Do the following: Open the heroic games launcher and go to: Settings < Advanced < Choose an alternative...