Django's development server does some very convenient things. One of them is service static media for the Admin site. When moving to a production server, in my case I was using nginx to host the static content, the media files were returning a 404.

I made two changes. In my settings.py file, I changed ADMIN_MEDIA_PREFIX to ADMIN_MEDIA_PREFIX = '/admin_media/'

In addition, I aliased /admin_media/ in my nginx config file.

location /admin_media {
    alias /usr/local/lib/python2.7/dist-packages/django/contrib/admin/media;
}

This may break your development server. Instead, I'm using this to start it.

python manage.py runserver --settings=www.settings-debug <server>:<port>

My debug settings file, settings-debug.py, is the same as the original settings in regards to ADMIN_MEDIA_PREFIX. That www might be different for you as that's the name of my site.