title: Paperclip Gem - "Image has contents that are not what they are reported to be" Error
body: <p>The website's function is to post a Blog Post. It's running locally on Windows 7. I've tried on Paperclip gem (both versions 4.2.4 and 4.3) and the server goes into an infinite loop in cmd (doesn't happen on 4.2.4 but still get the error). I did bundle install and it's definitely installed. </p>
  
  <p>Gemfile:</p>
  
  <pre><code>gem "paperclip", "~&gt; 4.3"
  </code></pre>
  
  <p>Here's the <strong>model:</strong></p>
  
  <pre><code>class Post &lt; ActiveRecord::Base
  
      has_attached_file :image, :default_url =&gt; ":style/rails1.jpg"
      validates_attachment_content_type :image, :content_type =&gt; /\Aimage\/.*\Z/
  
  end
  </code></pre>
  
  <p>This is the <strong>error</strong> I get when trying to submit an image (png or jpg):</p>
  
  <blockquote>
    <p>Image has contents that are not what they are reported to be</p>
  </blockquote>
  
  <p>I'm new to this so detailed explanations would be appreciated. I read some other fixes on here but nothing worked.</p>