My client is making me leave my games

Some times (like 4-5 times/week), when i want to play with my friends, we all click accept then my friends are sent to champion select and i get stuck in arranging team. They can see me in champion select and I can't select any champion so the game never starts and i have to wait 5 or more minutes try play again. I also repaired the game and uninstall the game then install it back.....no use. PLEASE help me riot.