I was able to edit a few lines in term-meta-box.php and got it working. Lines 34 (load-edit-tags.php -> load-term.php), 235 (edit-tags -> term), and 236 (removed completely) were all that was needed editing.
https://make.wordpress.org/core/2016/03/07/changes-to-the-term-edit-page-in-wordpress-4-5/
I think this is an issue with 4.5 as another plugin I was testing that adds an image field to terms isn't working either and it was before the update.
I have the same issue. Bought the term extension and it's not working on 4.5 for any taxonomies, custom or built-in.
