Error: Call to undefined function ‌‌wp_get_attachment_url()
  File "/app/source/public/wp-content/themes/planet4-master-theme/classes/class-p4-search.php", line 313, in P4_Search::get_results_offset
    $post_link      = isset( $post->custom['_wp_attached_file'] ) ? ‌‌wp_get_attachment_url( $post->id ) : $post->link;
  File "/app/source/public/wp-content/themes/planet4-master-theme/classes/class-p4-search.php", line 245, in P4_Search::set_paged_posts
    $live_posts_offset = $this->get_results_offset( $last_live_url, $this->posts );
  File "/app/source/public/wp-content/themes/planet4-master-theme/classes/class-p4-search.php", line 223, in P4_Search::get_paged_posts
    $search_async->set_paged_posts( $last_live_seen );
  File "/app/source/public/wp-includes/class-wp-hook.php", line 288, in WP_Hook::apply_filters
    $value = call_user_func_array( $the_['function'], $args );
  File "/app/source/public/wp-includes/class-wp-hook.php", line 312, in WP_Hook::do_action
    $this->apply_filters( '', $args );
...
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