Black Screen after Champion Selection

This doesn't happen every game, but when it does it's an extreme hinderance. After champion selection when everybody is loading into the game, i'll occasionally get a complete black screen, and then the game says bull crap that my firewall may be blocking the connection. I've disabled by firewalls when i play league and it still happens. This was the final straw that i deal with this crap, because I tried reconnecting to the game over 15 times for my last match and it cost me a leave on my game because I couldn't connect. SOMEBODY TELL ME HOW TO FIX THIS! It says firewall may be the issue, well, IT'S NOT. I have no firewall up at the time and it refuses to connect me. So either the enemy team is hacking the LoL servers so a couple people can't connect, or riot needs to fix their crap. This is ridiculous, and i'm tired of it hindering my games. I never leave games unless I absolutely have to in emergency.