Mastery Changing BUG

Okay so when i change my mastery's it says error and doesn't change them been doing it for past 2 days and am wondering if its only me and what i should do. Team reports me because my keystone for is Strength of age's. I have even tried using a different mastery page but the same message shows up and am stuck with same mastery page. Error "An unexpected error has occurred" If you keep encountering this error please check our support site or forum for more information.