https://bugs.winehq.org/show_bug.cgi?id=49446
--- Comment #7 from Wiwi datwiwi@gmail.com --- *noticing it wasn't clear
I ran into the "system.yaml trick". It didn't work for me, but doing a client repair and then restarting League of Legends worked for me.
Doing the repair after the "system.yaml tricket" and then killing wine processes and restarting the game worked for me.