Pop up of DEATH

Hello, so i love playing league but you know, not everyone can afford fast internet or a expensive computer/laptop. So it makes it hard to determine whether or not its the games fault or me being poor's fault. Anyway right to the point, i get in a game and all (doesnt matter game type) and we pick our champs and lock in but before the loading screen with all the portraits and stuff i get a pop up, mind you it can pop up once or twice or on good days not at all, and it really bugs me and makes the loading take forever. It says "cannot load.... if you have a firewall it maybe the cause...." something like that, i cant really read what it says because i've built a system where i know when it pops up and where to click the retry button. The retry button works but doesnt get rid of the fact that everyone is at 100% and im at 30%. I just want to know if it could be something else besides my crappy computer and internet, and i would like to know if anyone else gets this.

-Thx if you reply :D