Client screen goes black in blind pick

It usually happens that you cant write in pre-game lobby and there was once a bug that didn't allowed you to see your champs. For the second time tonight after everybody accepted the normal blind pick game the client went full black only conserving its frame, however the champ select music was still playing so you could assume that we were still in lobby, and after 20s i returned to the fully visible main screen with the game alert that a player failed to select.

I haven't noticed any other issues on the client after the game is disbanded, im using the official 6.16.16_08_05_12_30. Thanks for your time.