Multisite plugin development and wp_enqueue_script
As @Even commented, instead of url_to_postid(), you should be using something like this: if ( ! is_single() ) { return; } $post = get_post(); url_to_postid() is a round-about way of getting the ID of the current post, when WordPress has already determined what the current post is, i.e., it has already parsed the URL to … Read more