The related-user widget had two problems when dealing with avatars: one

on the server side, and one on the client.
On the server, if no avatar services were available for a user, we'd get

an uncaught AttributeError when trying to get the

get_avatar_urls_uncached method on a NoneType. On the client, once

we'd discovered a user without any avatars, we'd neglect to add a blank

avatarURL field to the data for the widget, resulting in a JavaScript

error.

Set the default avatar service to "None" and added an avatar-less user

to a group. Loaded that group in the admin UI and saw that I could see

the page, including the users widget, without any Python or JavaScript

errors.