[Client bug] "Disconnecting" when changing masteries

Three times in a row I can not change masteries.

First, the option is unresponsive while the champion ban phase is on. Then it goes gray-out and the client "freezes" [Even dough I can type on chat] In the end, the client displays a message "Temporarily disconnected.. wait/quit" whatever is it.

It keeps that message until the countdown is over and the game starts..

What is going on?

Edit: Now I can't even click on them since start.. I can just switch between the predefined pages but can't edit