title: Prestashop Class 'ProductCore' not found
body: <p>So first of all I am new to prestashop.
  I installed it and bought a theme.
  After installing the theme I get this error when I try to view my store
  (with error reporting on, otherwise it was a blank screen)</p>
  
  <pre><code>Fatal error: Class 'ProductCore' not found in /nfs/home/mywebsite.com/public_html/store/classes/Product.php on line 4
  </code></pre>
  
  <p>I haven't done anything with the codes...
  Why do I get this and how can I get rid of it?</p>