Cannot connect to HTTP Server

I've been playing a ranked game and it crashes due to the error "Cannot connect to the HTTP server". Thanks to this i have a lost ranked game and I'm doing my placements. My internet is working fine and it just doesn't allow me to connect back to the game. This is not fair since I am having a loss in my placements due to some random error. After the game was finished I am able to log back into league and carry on playing normally. What should i do?