Started few hours ago, players all over the world reported an error with their League Of Legends Client, Riot! is currently trying to rectify this problem as soon as they can.
Riot! have been having a rough few months following the earthquake in Japan and the gradual failing of their servers both EU and US with players all over the world reporting lags and buggy gameplay. Just this week, Riot! experienced gradual failing with their servers following the updates of their main game, League Of Legends, to version v.188.8.131.52, although the problem was apparently fixed, they nonetheless hit another wall today as their client is ridden with RADS error. I myself as a LoL player is affected by this and wishes Riot! to fix this as soon as they can, I NEED MY LoL FIX!
Riot! do have a diagnosis thread opened up, here