[Crash] Casting Abilities when Victory or Defeat sign comes up

Whenever the game ends (Victory or Defeat) and I cast some abilities, the client will freeze as I cast the ability and crash.

1. As the nexus dies, you cast any ability Or summoner. (I've had it crash using wards, flashes, or ults)

• Right after that the game freezes and for me, I need to restart my computer.

I'm not sure If It's just me, but this kind of annoys me. It's crashed for me using Crashed on when I used my upgraded sweeper. Crashed on When I jumped (W) Crashed on When I used my Ult (R)

Thanks