После обновления с Rails 5.0.1 до 5.2.0 произошло обновление в активном администраторе (с 1.0.0.pre5 до 2.6.0). Теперь я получаю:
An ActionView::Template::Error occurred in sessions#new:
couldn't find file 'active_admin/nested_menu_arrow.gif'
Checked in these paths:
/mnt/d/Project/Wittybrains/Optisom/clarityv2/app/assets/images
/mnt/d/Project/Wittybrains/Optisom/clarityv2/app/assets/javascripts
/mnt/d/Project/Wittybrains/Optisom/clarityv2/app/assets/stylesheets
/mnt/d/Project/Wittybrains/Optisom/clarityv2/vendor/assets/javascripts
/mnt/d/Project/Wittybrains/Optisom/clarityv2/vendor/assets/stylesheets
/root/.rbenv/versions/2.4.0/lib/ruby/gems/2.4.0/gems/lazy_high_charts-1.4.3/vendor/assets/javascripts
/root/.rbenv/versions/2.4.0/lib/ruby/gems/2.4.0/bundler/gems/activeadmin-ef1faccaef75/app/assets/javascripts
/root/.rbenv/versions/2.4.0/lib/ruby/gems/2.4.0/bundler/gems/activeadmin-ef1faccaef75/app/assets/stylesheets
/root/.rbenv/versions/2.4.0/lib/ruby/gems/2.4.0/bundler/gems/activeadmin-ef1faccaef75/vendor/assets/javascripts
/root/.rbenv/versions/2.4.0/lib/ruby/gems/2.4.0/gems/jquery-rails-4.3.5/vendor/assets/javascripts
/root/.rbenv/versions/2.4.0/lib/ruby/gems/2.4.0/gems/formtastic-3.1.5/app/assets/stylesheets
/root/.rbenv/versions/2.4.0/lib/ruby/gems/2.4.0/gems/actioncable-5.2.0/lib/assets/compiled
/root/.rbenv/versions/2.4.0/lib/ruby/gems/2.4.0/gems/activestorage-5.2.0/app/assets/javascripts
/root/.rbenv/versions/2.4.0/lib/ruby/gems/2.4.0/gems/actionview-5.2.0/lib/assets/compiled
/mnt/d/Project/Wittybrains/Optisom/clarityv2/app/assets/fonts
/root/.rbenv/versions/2.4.0/lib/ruby/gems/2.4.0/gems/font-awesome-sass-4.5.0/assets/stylesheets
/root/.rbenv/versions/2.4.0/lib/ruby/gems/2.4.0/gems/font-awesome-sass-4.5.0/assets/fonts
app/assets/stylesheets/active_admin.css.scss:9