How many times do I have to bring this to your attention, Riot, before I get a red post?

Mac client is a real piece of work. The old problem that required a "fix" around 4.17 or 4.18 is back; 50% of my games result in a black screen after champ select. If I ever am able to reconnect, it is about 30 minutes or so into the game, and obviously well beyond any hope of saving, but even if it were just 3 minutes into the game, that's still unacceptable. And then I get stuck with a practically permanent 20-minute lower-priority queue, because I can never get through a few solid games without this problem rearing its ugly head. Others have reported the same problem since season 5 began, and we've heard no word.