<% unless Spree::Config.facebook_app_id.nil? %>
  <% content_for :head do %>
    <meta property="og:title" content="<%= @product.name %>" />
    <meta property="og:type" content="product" />
    <meta property="og:url" content="<%= product_url(@product) %>" />
    <meta property="og:description" content="<%= @product.description %>" />
    <meta property="fb:app_id" content="<%= Spree::Config.facebook_app_id %>" />
  <% end %>

  <div id="fb-root"></div>
  <script>
    window.fbAsyncInit = function() {
      FB.init({
        appId      : "<%= Spree::Config.facebook_app_id %>", // App ID
        channelUrl : '//www.spreeworks.com/channel.html', // Channel File
        status     : true, // check login status
        cookie     : true, // enable cookies to allow the server to access the session
        xfbml      : true  // parse XFBML
      });

      // Additional initialization code here
    };

    // Load the SDK Asynchronously
    (function(d){
       var js, id = 'facebook-jssdk', ref = d.getElementsByTagName('script')[0];
       if (d.getElementById(id)) {return;}
       js = d.createElement('script'); js.id = id; js.async = true;
       js.src = "//connect.facebook.net/en_US/all.js";
       ref.parentNode.insertBefore(js, ref);
     }(document));
  </script>
  <div class="fb-like" data-send="false" data-width="450" data-show-faces="false"></div>
<% end %>

<% unless Spree::Config.facebook_app_id.nil? %>
  <% content_for :head do %>
    <meta property="og:title" content="<%= @product.name %>" />
    <meta property="og:type" content="product" />
    <meta property="og:url" content="<%= product_url(@product) %>" />
    <meta property="og:description" content="<%= @product.description %>" />
    <meta property="fb:app_id" content="<%= Spree::Config.facebook_app_id %>" />
  <% end %>

  <div id="fb-root"></div>
  <script>
    window.fbAsyncInit = function() {
      FB.init({
        appId      : "<%= Spree::Config.facebook_app_id %>", // App ID
        status     : true, // check login status
        cookie     : true, // enable cookies to allow the server to access the session
        xfbml      : true  // parse XFBML
      });

      // Additional initialization code here
    };

    // Load the SDK Asynchronously
    (function(d){
       var js, id = 'facebook-jssdk', ref = d.getElementsByTagName('script')[0];
       if (d.getElementById(id)) {return;}
       js = d.createElement('script'); js.id = id; js.async = true;
       js.src = "//connect.facebook.net/en_US/all.js";
       ref.parentNode.insertBefore(js, ref);
     }(document));
  </script>
  <div class="fb-like" data-send="false" data-width="450" data-show-faces="false"></div>
<% end %>

Remove channelUrl from FB.init call
Remove channelUrl from FB.init call
