title: WooCommerce - t.product_variations is undefined
body: <p>I am developing a WooCommerce website with a custom theme (copied the templates etc)</p>
  
  <p>Anyhow, when viewing a product with variations, I am unable to see the cart button. Once my selection is made, no cart button appears. </p>
  
  <p>There is a JS error: <code>t.product_variations is undefined</code>.</p>
  
  <p>All variations are set correctly.</p>
  
  <p>I've read of many threads saying the cart button does not appear, but nothing so far seemes to have solved my specific problem - and no mentioned of my JS error. Here's what I have tried so far:</p>
  
  <ol>
  <li>Checked the wp_footer() function is called (it is)</li>
  <li>Removed all of my own JS to avoid possible collisions (doesn't make any difference)</li>
  <li>Made sure all product options have a price etc (tried with and without)</li>
  <li>Tried disabling plugins (only one other plugin used - Advanced Custom Fields - makes no difference)</li>
  <li>Switched to a default theme 'twentytwelve'. When I do this, <strong>it does work</strong>...</li>
  </ol>
  
  <p>So, switching theme indicates to me that I may have removed something or destoryed something causing this problem in my theme, but I cannot understand what or how.</p>
  
  <p>I am using the latest WP installation and the latest WooCommerce plugin available as of this writing.</p>
  
  <p>I would really appreciate some help on this! <em>Anything</em> really to lead me on the right path.</p>
  
  <p>Many thanks,
  Mikey.</p>
  
  <p><strong>Screenshot of error:</strong>
  <img src="https://i.stack.imgur.com/u1HXg.png" alt="enter image description here"></p>