Additional Fields Not Working in Appointments +

Hi,

I've have been trying to use the additional fields add on in Appointments plus for a while now and for some reason it just isn't working for me.

I've activated the add on and it shows up in the settings page but when I fill out the field label and type then press add nothing happens. The page does not reload, it is not added to the appointment form. One thing I did notice is that when I activate the additional fields add on the Save button on the settings page disappears. I'm not sure if that has anything to do with it.

I have also deactivated all other plugins and changed the theme to see if any of that was interfering with Appointments+ but the problem still persisted. I've attached a screenshot of the additional fields portion in settings. The screenshot is taken AFTER I have pressed the add button.

Adding additional fields is very important to us and the reason we purchased this plugin. Other than this issue it has been working great for us. Thank you!