Edit file File name : ms-admin-filters.php Content :<?php /** * Multisite Administration hooks * * @package WordPress * @subpackage Administration * @since 4.3.0 */ // Media hooks. add_filter( 'wp_handle_upload_prefilter', 'check_upload_size' ); // User hooks. add_action( 'user_admin_notices', 'new_user_email_admin_notice' ); add_action( 'network_admin_notices', 'new_user_email_admin_notice' ); add_action( 'admin_page_access_denied', '_access_denied_splash', 99 ); // Site hooks. add_action( 'wpmueditblogaction', 'upload_space_setting' ); // Network hooks. add_action( 'update_site_option_admin_email', 'wp_network_admin_email_change_notification', 10, 4 ); // Post hooks. add_filter( 'wp_insert_post_data', 'avoid_blog_page_permalink_collision', 10, 2 ); // Tools hooks. add_filter( 'import_allow_create_users', 'check_import_new_users' ); // Notices hooks. add_action( 'admin_notices', 'site_admin_notice' ); add_action( 'network_admin_notices', 'site_admin_notice' ); // Update hooks. add_action( 'network_admin_notices', 'update_nag', 3 ); add_action( 'network_admin_notices', 'maintenance_nag', 10 ); // Network Admin hooks. add_action( 'add_site_option_new_admin_email', 'update_network_option_new_admin_email', 10, 2 ); add_action( 'update_site_option_new_admin_email', 'update_network_option_new_admin_email', 10, 2 ); Save