Firewall error during character load

Hey guys so i keep getting the firewall error right after i select my character and the game tries to load. It stays black for a few moments then the firewall error pops up. I am currently at my college and have no access to routers or motems or any of that. This happened to me a few weeks ago as well and i was never able to fix the problem so i just stopped playing. I have triple checked and i have no firewall on or any sort of blockers on. I was playing last night at home and had no issues at all with this. Now i come back to college and the firewall error occurs again. I have emailed RIOT but they were unable to help me fix the problem...Please can anyone help me fix this.