rails: application.css Failed to load resource: the server responded with a status of 404 (Not Found)
<p>I pushed some code to heroku and my app broke.
I got this errors in browser console:</p>

<blockquote>
  <p><a href="https://agile-mesa-47878.herokuapp.com/javascripts/application.js" rel="nofollow noreferrer">https://agile-mesa-47878.herokuapp.com/javascripts/application.js</a> Failed to load resource: the server responded with a status of 404
  (Not Found)   2
  <a href="https://agile-mesa-47878.herokuapp.com/stylesheets/application.css" rel="nofollow noreferrer">https://agile-mesa-47878.herokuapp.com/stylesheets/application.css</a>
  Failed to load resource: the server responded with a status of 404
  (Not Found)</p>
</blockquote>

<p><a href="https://i.stack.imgur.com/Is6mW.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Is6mW.png" alt="enter image description here"></a></p>

<p><a href="https://i.stack.imgur.com/z4pv3.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/z4pv3.png" alt="enter image description here"></a></p>

<p>This happened second time today. After first I just pushed new code to server and it started working. But now I am starting worrying if something is wrong.
 Locally it works fine</p>

<pre><code>My application.js file
// This is a manifest file that'll be compiled into application.js, which will include all the files
// listed below.
//
// Any JavaScript/Coffee file within this directory, lib/assets/javascripts, vendor/assets/javascripts,
// or any plugin's vendor/assets/javascripts directory can be referenced here using a relative path.
//
// It's not advisable to add code directly here, but if you do, it'll appear at the bottom of the
// compiled file.
//
// Read Sprockets README (https://github.com/rails/sprockets#sprockets-directives) for details
// about supported directives.
//
//= require jquery
//= require jquery.turbolinks
//= require jquery_ujs
//= require bootstrap
//= require_tree .
//= require turbolinks
</code></pre>

<p>My application.css file</p>

<pre><code>/*
 * This is a manifest file that'll be compiled into application.css, which will include all the files
 * listed below.
 *
 * Any CSS and SCSS file within this directory, lib/assets/stylesheets, vendor/assets/stylesheets,
 * or any plugin's vendor/assets/stylesheets directory can be referenced here using a relative path.
 *
 * You're free to add application-wide styles to this file and they'll appear at the bottom of the
 * compiled file so the styles you add here take precedence over styles defined in any styles
 * defined in the other CSS/SCSS files in this directory. It is generally better to create a new
 * file per style scope.
 *
 *= require bootstrap
 *= require_tree .
 *= require_self
 *= require_custom
 */
</code></pre>