title: PDF display issue in iFrame once upload using Paperclips in Rails
body: <p>I am working on <code>Rails application</code> where uploaded <code>PDF</code> using <code>Paperclip Gem</code>. Now try to <code>display PDF</code> using below HTML code.</p>
  
  <blockquote>
    <blockquote>
      <p>Upload PDF settings</p>
    </blockquote>
  </blockquote>
  
  <pre><code>has_attached_file :agreement
  validates_attachment_content_type :agreement, :content_type =&gt;["application/pdf"]
  
  &lt;iframe src="/system/contracts/agreements/000/000/022/original/pdf_ag.pdf" align="middle" style="width: 100%; height:720px;" frameborder="0"&gt;&lt;/iframe&gt;
  </code></pre>
  
  <blockquote>
    <blockquote>
      <p>But got error below</p>
    </blockquote>
  </blockquote>
  
  <pre><code>error : ActionView::MissingTemplate (Missing template sessions/unknown_route, application/unknown_route
  
  No route matches [GET] "/system/contracts/agreements/000/000/022/original/pdf_ag.pdf"
  </code></pre>
  
  <p>I tried but same issue again and again. Let me know if any one have idea or trick.</p>
  
  <p>Thanks</p>