Bug with LUX in Arram

Hey, i just played an aram and suddenly i wasnt able to cast my e again. I just casted my q e combo in the bush and i already wondered cause i couldnt see nocturne who was obviously in that bush. My E never explode and since then i couldn cast it again. it was grey like i didnt leveld it and nothing helped. I relogged 2 times and swichted smart cast off and on. I selected another key but nothing worked. Heres a screen of it - pretty strange! I play LOL since a long time now but someting like that never happened before! http://www.bilder-upload.eu/show.php?file=e12510-1444469218.png