I just installed MainStage 3.2.4 from the app store and now I can't change ANY mapping/assignments in my concerts. I can get the pop-up dialog box to show up but now of the drop-down menus respond (all I can do is change the name). This is true for both pre-existing mappings in the concert or any I add to the concert.

MacBook Pro with Retina display, OS X El Capitan (10.11.1)