11/25/2013 at 1:57 pm #274291
I see you replied a couple times while I was drafting my initial reply…
What you did to get it to work on the public side of your site is you set the Medium image size to the correct size for the template so it didn’t need to create them dynamically. In the admin, they are still being created dynamically which is why you’re seeing the loading spinner. My suggestions from my previous reply still apply.