My avatar as the super admin user, actually a gravatar, appears in every subdirectory site I am in, including the top level site.
One of my new users has been adventurous enough to add his avatar to the system. He did a direct upload of the image, so it’s a different source than mine. It shows up in the top level site, but appears in the member list of the subdirectory site he’s in as a ‘broken image’ – i.e., the file is evidently not being found. I did a search of this forum for this problem but didn’t see anything with the search terms I tried. Is this a known issue? Is there a toggle somewhere he should have flicked?