JezK
Edit File: update.php
<?php /** * Update/Install Plugin/Theme network administration panel. * * @package WordPress * @subpackage Multisite * @since 3.1.0 */ if ( isset( $_GET['action'] ) && in_array( $_GET['action'], array( 'update-selected', 'activate-plugin', 'update-selected-themes' ), true ) ) { define( 'IFRAME_REQUEST', true ); } /** Load WordPress Administration Bootstrap */ require_once __DIR__ . '/admin.php'; require ABSPATH . 'wp-admin/update.php';