[CLIENT] Masteries Not Closing in Team Builder

If I've opened another summoner's mastery page recently, their pages will show up for me in the drop down menu in Team Builder. If I open the 'edit' button for the masteries, I can't click the exit button. Nothing happens, so i'm stuck without being able to click any other buttons including the X button for the client. Happened to me and a couple of friends, pretty inconvenient especially if you've waited for a group only to have to close the client.