SOLUTION for "You have been disconnected. Please check your internet conenction and try again."
I though i'd write it here. I know it's wrong section of boards, but it's the most popular one.
I think it's the most common thing that happens in loading screen when things go awry.
Solution for that: Open League of legends main page and try to reconnect again. (Just press Game Info in top left corner of boards) That's it. You should reconnect to your game!
Some of you might have known about this, but I really hope this will help at least 1 unlucky player out there.