[CLIENT][CRASH] Crash in game caused a reset of my client settings

It happened to me 2nd time recently, so i decided to share it here. Here's how it keeps working (or rather not working): In game, like 20 min in or so, I started to lag for a few seconds, then i lost connection ("Attempting to reconnect"), even tho my internet connection was fine. Even after resetting the connection, i couldn't go back to game. I had to close League by Task Manager, then launch League again. Next game i tried to play i noticed that some settings (like voice chat settings) were at its default state, my runes had been reset (and i had the pop-ups like after first playing, the ones that tell you how it works) and after picking the champion i had to change my skin, since it was set back to the default one. This time the game didn't even load, after the end of countdown i was left with the client open with message "the game is in progress", but the other window wasn't opening. This time i had to turn my whole PC off and on to make it work, but luckily the team had enough time to remake the game, so noone got punished for that. In client i noticed other things changed, e.g. my champions were sorted alphabetically instead of mastery (how i left that). I have no idea what may be causing this, but im sure it is not something on my side, since all other times League is working as intended and i didn't make any changes to the PC.