Fields Builder no longer functioning

When in Admin -> Profile Fields -> Fields Builder -> Join Form it is constantly loading and does not pull up any form info. The other 3 fields (edit profile, view profile and search profiles) only show a button with owner/admin When you click it, it does nothing. I could have sworn I was able to edit in this section. Anyone experiencing this or know how to fix it?

Hi there!  I had the same problem.  I fixed it by choosing a Default language.  I had 2 language files (French and English) on my site but none selected.  I chose English as my default language (top of the Language Setting page), then cleaned All Cache from the main Admin page and voila, the problem was fixed, my Fields Builder page was loading again.  :)

I hope this helps.