I just pulled the latest commits and tested invisible groups.
In short, invisible groups cannot be edited in the admin interface. It appears in the list, but selecting it shows a spinner but no editing template. Instead, I see a
403 Forbidden result in my dev server console while processing
At a glance, I’d guess that app/models/user.rb:112 is too restrictive, but I’m far from understanding the codebase enough to propose a fix.