Created a file dump and now League runs like shit

I have received the infamous "A Critical Error Has Occurred..." pop-up when i was loading into a game, then pop-up then prompted me to do a file dump which i did. Then the error occurred again and i did the small dump after that one. After all this when i finally got into a game the game seemed fine for a minute and then after I had a Windows Update, when i got back on the client and in the game, I was hard stuck at 15-17 FPS when previously i was running at 60+. Need some help on restoring League back to where i can actually play it efficiently.