title: woo commerce products not displaying in admin
body: <p>After upgrading to woo-commerce 2.2.8 , I've run into this weird issue..</p>
  <p>everything is intact.. including the frontend shop and products .. but products are not showing in the admin page!!</p>
  <p>after hours of scratching my head I happened to check in the console and there seems to be a javascript error that's causing the products from not showing up!! it looks like this:</p>
  <blockquote>
  <p>'wp' is not defined</p>
  <p>File: meta-boxes-product-variation.min.js, Line: 122, Column: 18</p>
  </blockquote>
  <p>I really don't know what to do... do I need to replace this file ?</p>