no fields appear

Spoke to @stavroch , and found the problem in his functions.php file he had a custom to re order the checkout fields that was interfering with the plugin

the function was

////change order of billing details...
add_filter("woocommerce_checkout_fields", "order_fields");

function order_fields($fields) {

$order = array(
"billing_last_name",
"billing_first_name",
"billing_company",
"billing_email",
"billing_phone",
"billing_address_1",
"billing_address_2",
"billing_postcode",
"billing_country"
);
foreach($order as $field)
{
$ordered_fields[$field] = $fields["billing"][$field];
}

$fields["billing"] = $ordered_fields;
return $fields;

}