Masteries Bug [Client and In-Game] Not Being Able to Create New Mastery Pages in Champ Select

I've played two ranked games today and with both of the games I can't create a mastery page and a message with "error" is popping up. . Does anyone else have this bug and if so how do you fix this?

(Bug when you are choosing masteries, it has happened when I have made a new mastery page but I haven't tried with old pages yet. Whenever I try to save or switch to a new page it will come up with the "error" message. This has happened in all my games I have played so far today.)

Update: The pages I created in champ select (well before the timer ran out and I did press save each time, I only started having the error problem after the first game) were not saved when I looked at them out of champ select though I do remember being able to save my first page but it still didn't show up in-game.