Same bug here, I’m on 4.7.5. I figured out what the issue was though. In “action-admin.js”, on line 83, change “window.ama_fav = jQuery.parseJSON(response);” to “window.ama_fav = response;”.
It looks like jQuery is trying to parse json while the response is already json.. For some reason jQuery doesn’t recognize the datatype.. Applying the above changes fixed the issue for me.