Self cast not working

I was playing a premade AI game where I played as lee sin, I press alt+w for lee sin shield and the spell did not go off. I check the control keys menu and the self cast has alt + w list for self cast and the others skills as well. So I restarted my client to check if the problem is solved. But no, still no self cast. Also did the client, "Initiate Full Repair" options. Still no self cast. Please fix.