501 error after applying SUPEE-9767

[husseycoding]

One customer reports the following:

After we applied "SUPEE-9767 - Important Magento Security Patch" the below code in "HusseyCoding_AjaxCartPopup_CartController" not working and we are getting 501 internal server error.

if (Mage::helper('ajaxcartpopup')->getCartItemCount() > $countbefore):
    $allitems = Mage::getSingleton('checkout/cart')->getItems()->getData();
    $itemid = array_pop($allitems);
    $itemid = $itemid['item_id'];
    $deleteurl = Mage::helper('ajaxcartpopup')->getDeleteUrl($itemid);
endif;