autoship_no_address_notice (filter)

( templates/scheduled-orders/order-address-template.php) Allows you to customize the message displayed to the customer when either a Shipping and/or Billing address is currently empty for the associated Scheduled Order. The filter takes the $notice to be displayed, the context ($address_type) in which it's being displayed ( either shipping or billing ) and the associated $scheduled_order.

Example 

// Customize notice displayed for customers missing addresses
function xx_custom_no_address_notice ($notice, $address_type, $scheduled_order){
    if($address_type == 'Shipping'){
        return '<h6 class="notice-red">You have no Shipping Address on file, please edit the address in My Account > Addresses</h6>';
    }
    elseif ($address_type == 'Billing') {
        return '<h6 class="notice-red">You have no Billing Address on file, please edit the address in My Account > Addresses</h6>';
    }
}
add_filter('autoship_no_address_notice', 'xx_custom_no_address_notice', 10, 3);