Unable to use spells. Gameplay

I was playing a round as Lux on Summoners Rift, blind pick. Everything worked as it should until somewhere around lvl 10. After this point, whenever I tried to use my E, nothing would be cast and I would receive an error code saying something like "You cannot cast that spell right now". The icon of the spell was "greyed" out, as if I hadn't put any points in it even though it was maxed. I tried leaving the game and reconnecting as well as leaving the game, close the client, reopen it and reconnect, without luck.

I bought