I\'m getting that error on my production server, and can\'t figure out why. It happens when running this command:
bundle exec rake assets:precompile RAILS_EN
This is most likely due your config/application.rb not requiring rails/all (the default), but some custom requires.
config/application.rb
rails/all
To resolve this, add the following to config/application.rb:
require 'sprockets/railtie'