Katarina - cant use q or r

Last game i played with Katarina, at the end of the game i couldnt use my q or r. We just did drake, i think i could still use the abilities at that moment, i ran at their base and i couldnt trow a knife or start my ult near enemies. The game was almost over so i had plenty of time to try it. When i pressed q, the marker still showed up but i couldnt use it at enemies or minions. At the final fight at their nexus i could still jump in with e, spin around with w but couldnt do my ulti (it was not on cooldown).