'Manage fields' and 'manage display' links not working

I did an update of several modules (core included, from 7.xx to 7.26), a couple of weeks ago, and until now I had not tried to access content types.

Today I did, but while I can see the 'manage fields' and 'manage display' links, when I click on them I'm taken to the 'edit' page. Also, if you have admin_menu installed and just hover on structure/content-type/custom-content-type, a menu with the available edit options appears, but in my case only the 'delete' option is there.

Searching around I see this is most commonly caused by the 'field ui' module being disabled, but I checked and it's in fact enabled. I disabled/re-enabled it but nothing happened.

Per this post, I also tried enabling all checkboxes at admin/config/administration/admin_menu under the 'performance' tab, flushed caches, and still no result.

I did the site's update for a client, and still have a version of the site on localhost, where all menus work fine. I sent them all files/database so their hosting provider would upload the site and now this issue comes up. I have no access to the database, only the admin pages. What else could be the problem and how could I fix it?

Thank you in advance.