FireWall Error? After 5-20 min in the game.

For the past weeks ive been hacing the error Fire wall is blocking your connection... Its very annoying, Sometimes i reconnect but.. when i reach 100 percent in me loading it says there is a problem with your internet connection try again, then it says my game has crashed on top of the reconnect button. ive tried reconecting 4-9 more times nothing happend... i uninstalled and reinstalled league of legends 1 time still nothing worked.. i get low priority queue's which isnt fair for something that isnt my fault! riot please fix this! i want to play... sometimes my game works and sometimes it doesnt, but i have something that can help for riot whenever i get over 400 ping and lag from my ping not riot it attempts me to reconnect then from there i get the firewall issue, and my game lasts from 15 min or 25 min then i crash its random... please help riot!