As I've said to other people tonight.
Ever used any work arounds that caused you to change some LoL files?
If you did that, change back to normal, if you dunno how, reinstall ftw!
Or it might be a router problem, ports might not be opened for LoL. Is it at your home and do you have a chance to maybe restart your router? If that doesn't work, open the LoL ports for Maestro server and so on. The ports you need should be on the site somewhere. But i slack, and cba to find 'em myself and give 'em to ya D: