Block requests to WP Ultimo's licensing servers

block_ultimo_http_requests.php

<?php
// WP Ultimo's licensing servers have gone offline and are causing
// customer networks to have long load times or error out completely.
// Blocking the requests to Ultimo's servers resolves this issue.
//
// H/T Calvin Alkan for suggesting http request filtering as a possible solution

add_filter('pre_http_request', 'block_ultimo_http_requests', 10, 3);

function block_ultimo_http_requests($preempt, $parsed_args, $url) {
    // Define the domains to block
    $blocked_domains = [
        'wpultimo.com',
        'nextpress.co',
        'nextpress.us'
    ];
    
    // Parse the URL to get the host
    $parsed_url = wp_parse_url($url, PHP_URL_HOST);
    
    // Check if the host contains any of the blocked domains
    foreach ($blocked_domains as $domain) {
        // Check if the blocked domain string is present in the parsed URL's host
        // Note that a more robust regex would be preferrable to simple strpos check
        if (strpos($parsed_url, $domain) !== false) {
            // Block the request by returning a WP_Error
            return new WP_Error('blocked_url', 'Blocked URL: ' . $url);
        }
    }
    
    return $preempt;
}