Had to dodge a game B/C new client doesn't let me change masteries.

Title says it all, I was frantically trying to pick in my masteries for 30 seconds, but switching mastery pages or filling in the mastery boxes didn't work. Box just stayed blank or the page didn't change, resulting in me having to dodge a game to not get the wrong mastery page. On top of the mastery page already now being garbage that fills up the entire screen, it doesn't even work.