Masteries of other player is showing when we are building a game - if we edit then lol stucks

Masteries of other summoner is shown when we view their profile while building a game - and editing masteries window close button doesn't work.

Step to reproduce - 1- Go to the "building a game" screen , and select the role and position, don't select champion (eg - bottom lane+marksmen). 2 -when champion selection screen comes, press ESC (to go out of champion selection screen). 3 -Now open the chat and click on "Recently played", click any player and view his/her profile (View Profile) 4 -Go to masteries page of that player, and click some of his masteries - like check his masteries. 5 -Now go back to building a game by clicking on its home button. 6 -Select a champion, now the masteries shown in drop down will be of the player which u recently viewed profile. If you select any of them, u get error.. and if try editing by clicking on Edit button, then your mastery page opens but cllse button doesn't work.