Was playing Varus in a ranked match and about halfway through it my q just stopped working

Just had a bug on Varus where his Q would not go off no matter what I did. I tried clicking on the skill, pressing q, alt tabbing back in and out and nothing would work. It did not fix itself after death. I posted about this on a League of Legends group on facebook and they told me a fix for it is to toggle smart casting on/off but that really didn't help that fact that I lost a ranked game because of it and I can't help but feel sour about the loss. The other thing is that other people in the group are also saying they had this problem with all champions who have a q that is a charge up type ability I at least ask that you disable or even provide a warning in the client about this bug we should have won that game but since I lost my q halfway through we were steamrolled.