Rails 4: assets not loading in production

Question

In rails 4 you need to make the changes below:

config.assets.compile = true
config.assets.precompile =  ['*.js', '*.css', '*.css.erb'] 

This works with me. use following command to pre-compile assets

RAILS_ENV=production bundle exec rake assets:precompile

Best of luck!

I just had the same problem and found this setting in config/environments/production.rb:

# Rails 4:
config.serve_static_assets = false

# Or for Rails 5:
config.public_file_server.enabled = false

Changing it to true got it working. It seems by default Rails expects you to have configured your front-end webserver to handle requests for files out of the public folder instead of proxying them to the Rails app. Perhaps you've done this for your javascript files but not your CSS stylesheets?

(See Rails 5 documentation). As noted in comments, with Rails 5 you may just set the RAILS_SERVE_STATIC_FILES environment variable, since the default setting is config.public_file_server.enabled = ENV['RAILS_SERVE_STATIC_FILES'].present?.

In /config/environments/production.rb I had to add this:

Rails.application.config.assets.precompile += %w( *.js ^[^_]*.css *.css.erb )

The .js was getting precompiled already, but I added it anyway. The .css and .css.erb apparently don't happen automatically. The ^[^_] excludes partials from being compiled -- it's a regexp.

It's a little frustrating that the docs clearly state that asset pipeline IS enabled by default but doesn't clarify the fact that only applies to javascripts.

I was able to solve this problem by changing: config.assets.compile = false to
config.assets.compile = true in /config/environments/production.rb

Update (June 24, 2018): This method creates a security vulnerability if the version of Sprockets you're using is less than 2.12.5, 3.7.2, or 4.0.0.beta8