Vel'koz Ult bug

I'd like to add to that. It was either a time related bug or too many inputs but I was unable to cast Vel'Koz's ult in Howling Abyss - ARAM mode. My specific instance occurred when dying while dishing out q, w, e, then finishing with a ult but I died as it casted. It went through its cooldown but remained uncastable for the rest of the match.

I've experienced this bug many times. It usually starts with your ult being interrupted right before death. Next time u try and ult, it doesn't work. The work around that i found to this bug is to ctrl+Alt+Del, end task (kill league), and log back in.