Disconnection and black screen

Installed lol a few days ago was working fine until i tried playing today. After champion selection it gives a black screen and a massage that i have been disconnected. I tried using a wired connection but it seems the internet connection is not the problem since everything else is working fine. I also disabled Firewall and all the anti-virus software but with no progress. It also seems that my characters gets in game since it says that i am still in game which is quite sad for my team .... having a afk player .... any suggestions are welcome.