enable the public file server for static assets

config/environments/production.rb

@@ -16,7 +16,7 @@ Rails.application.configure do
 
   # Disable serving static files from the `/public` folder by default since
   # Apache or NGINX already handles this.
-  config.public_file_server.enabled = ENV['RAILS_SERVE_STATIC_FILES'].present?
+  config.public_file_server.enabled = true
 
   # Compress JavaScripts and CSS.
   config.assets.js_compressor = :uglifier