Issue with making masteries with the new launcher

Hi,

It's happened to me twice. So when i was in the pre-game lobby, as I chose my champion, I had to make a new masteries page. However, I was unable to do it twice in 2 days, I kept on clicking to add points but: nada. I had to reboot my launcher. I don't know if it only happened to me or if other players encountered the bug. If it is the case, please release a fix as soon as possible because it'd be really annoying to experience this in a ranked pre-game lobby.

Thank you