Black Screen Connection Error.

i am encountering this problem more and more these past few months, i join a match wether draft or aram or a mod, we select the champs and then we go to the preMatch loading screen, and to my surprise i get a black screen and after a minute or two of waiting i get a small pop up saying that i failed to connect to the server and please try again. clicking try again many times won't help, restarting my connection won't help, even restarting my PC won't help. i will only be able to play again if and only when the match is over, i get thrown into the scoring screen with a message saying that i didnt get any xp or IP because i was AFK most of the match