title: Woocommerce wc-ajax returns html response
body: <p>The problem is in the checkout page, "Your Order" section is always grayed out and spinner is loading forever.</p>
  
  <p>I turned off <strike>https</strike>, Cloudflare, All the Plugins, Activated default theme, same behavior persisted.</p>
  
  <p>I tried to debug what is happening, when i reach the checkout page through Chrome Dev, Network tab:</p>
  
  <p>an XHR POST request gets sent to /checkout/?wc-ajax=update_order_review</p>
  
  <p>This is where it gets weird, the response that is returned with code 200 is actually an HTML response with the same page rather than JSON object, and the reponse headers are:</p>
  
  <pre><code>Request URL:https://alpha.seniorinafashion.com/checkout/?wc-ajax=update_order_review
  Request Method:POST
  Status Code:200 
  Remote Address:104.31.91.108:443
  Response Headers
  cache-control:no-cache, must-revalidate, max-age=0
  cf-ray:3312009e9e431a99-DUS
  content-encoding:br
  content-type:text/html; charset=UTF-8
  date:Tue, 14 Feb 2017 16:47:31 GMT
  expires:Wed, 11 Jan 1984 05:00:00 GMT
  link:&lt;https://alpha.seniorinafashion.com/?p=2724&gt;; rel=shortlink
  link:&lt;https://alpha.seniorinafashion.com/wp-json/&gt;; rel="https://api.w.org/"
  server:cloudflare-nginx
  set-cookie:woocommerce_cart_hash=771886deccd483983b22b6a8ac26f76e; path=/
  set-cookie:wp_woocommerce_session_d3fe2e799745c6650de3e94ad8c9e5b5=59cfc776e38750ac597b0cc8396dca00%7C%7C1487260661%7C%7C1487257061%7C%7C887c63ae5a0e78a8c86f7622f03cd2d2; expires=Thu, 16-Feb-2017 15:57:41 GMT; Max-Age=169810; path=/
  set-cookie:woocommerce_items_in_cart=1; path=/
  set-cookie:woocommerce_cart_hash=771886deccd483983b22b6a8ac26f76e; path=/
  set-cookie:wp_woocommerce_session_d3fe2e799745c6650de3e94ad8c9e5b5=59cfc776e38750ac597b0cc8396dca00%7C%7C1487260661%7C%7C1487257061%7C%7C887c63ae5a0e78a8c86f7622f03cd2d2; expires=Thu, 16-Feb-2017 15:57:41 GMT; Max-Age=169810; path=/
  set-cookie:woocommerce_items_in_cart=1; path=/
  status:200
  x-frame-options:SAMEORIGIN
  x-pingback:https://alpha.seniorinafashion.com/xmlrpc.php
  Request Headers
  :authority:alpha.seniorinafashion.com
  :method:POST
  :path:/checkout/?wc-ajax=update_order_review
  :scheme:https
  accept:*/*
  accept-encoding:gzip, deflate, br
  accept-language:en-US,en;q=0.8
  content-length:836
  content-type:application/x-www-form-urlencoded; charset=UTF-8
  cookie:__cfduid=dcd5da450805c7fb21259f27cb677e8b51487087855; woocommerce_items_in_cart=1; woocommerce_cart_hash=771886deccd483983b22b6a8ac26f76e; wp_woocommerce_session_d3fe2e799745c6650de3e94ad8c9e5b5=59cfc776e38750ac597b0cc8396dca00%7C%7C1487260661%7C%7C1487257061%7C%7C887c63ae5a0e78a8c86f7622f03cd2d2
  origin:https://alpha.seniorinafashion.com
  referer:https://alpha.seniorinafashion.com/checkout/
  user-agent:Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36
  x-requested-with:XMLHttpRequest
  Query String Parameters
  view source
  view URL encoded
  wc-ajax:update_order_review
  Form Data
  view source
  view URL encoded
  security:47743ef2c2
  payment_method:cod
  country:DE
  state:
  postcode:
  city:
  address:
  address_2:
  s_country:DE
  s_state:
  s_postcode:
  s_city:
  s_address:
  s_address_2:
  post_data:billing_first_name=&amp;billing_last_name=&amp;billing_company=&amp;billing_email=&amp;billing_phone=&amp;billing_country=DE&amp;billing_address_1=&amp;billing_address_2=&amp;billing_postcode=&amp;billing_city=&amp;billing_state=&amp;account_password=&amp;shipping_first_name=&amp;shipping_last_name=&amp;shipping_company=&amp;shipping_country=DE&amp;shipping_address_1=&amp;shipping_address_2=&amp;shipping_postcode=&amp;shipping_city=&amp;shipping_state=&amp;order_comments=&amp;shipping_method%5B0%5D=flat_rate%3A1&amp;payment_method=cod&amp;terms-field=1&amp;_wpnonce=794e840694&amp;_wp_http_referer=%2Fcheckout%2F
  shipping_method[0]:flat_rate:1
  </code></pre>