title: Why is my Sinatra app showing a blank screen?
body: <p>My Sinatra app was working on my local server a few days ago, but now it simply isn't running, and all I get is a blank screen. Even when I deploy to Heroku, nothing works. </p>
  
  <p>Here's a GitHub repository where you can check out my code: <a href="https://github.com/aayalur/Sinfoursq" rel="nofollow">https://github.com/aayalur/Sinfoursq</a></p>
  
  <p>I think the problem is with my <code>config.ru</code> file.</p>
  
  <pre><code># Gemfile
  #require "rubygems"
  #require "bundler/setup"
  #require "sinatra"
  
  require "./main"
  
  set :run, false
  set :raise_errors, true
  
  run Sinatra::Application
  </code></pre>
  
  <p>Thanks!</p>