Error editing a user in admin view (rails 6)

[saracarl]

I created a new user and then went in to the admin dashboard to edit it and change it into an owner. I couldn't edit the user because:

  app/controllers/application_controller.rb:209:in `load_html_blocks'
  Rendering admin/edit_user.html.slim
  Rendered admin/edit_user.html.slim (Duration: 66.3ms | Allocations: 17434)
Completed 500  in 146ms (ActiveRecord: 18.7ms | Allocations: 28847)

NoMethodError - undefined method `print_name' for #<User:0x000055568482afc0>:
  app/views/admin/edit_user.html.slim:12
  app/views/admin/edit_user.html.slim:3

Same thing happens when I try to edit an owner in the same dashboard.

[saracarl]

We should test this against rails4, too, because I suspect it will be a problem there. (And I need that to work -- I edit owners a lot.)