Fix timeout when menus are saved when Automatic Cache Purging of SG Optimizer plugin is enabled. Add code to `functions.php` of your WordPress theme.

sg-cachepress-fix-timeout-menu-save.php

<?php

/**
* Prevent timeout when menus are saved when Automatic Cache Purging of SG Optimizer plugin is enabled.
*/
add_action( 'save_post_nav_menu_item', 'sg_cachepress_remove_purge_all_post_cache' );

function sg_cachepress_remove_purge_all_post_cache() {
	global $wp_filter;

	foreach ( $wp_filter['save_post'] as $actions ) {
		foreach ( $actions as $action ) {
			// Check callback function.
			if ( ! array_key_exists( 'function', $action ) ) {
				continue;
			}

			$function = $action['function'];

			// Check `purge_all_post_cache` callback function.
			if ( ! is_array( $function ) || 'purge_all_post_cache' !== $function[1] ) {
				continue;
			}

			// Remove actions.
			remove_action( 'save_post', $function, 10 );

			remove_action( 'save_post_nav_menu_item', 'sg_cachepress_remove_purge_all_post_cache' );

			return;
		}
	}
}

add_action( 'wp_update_nav_menu', 'sg_cachepress_purge_everything');

function sg_cachepress_purge_everything() {
	// Check SG Optimizer Supercacher.
	if ( ! function_exists( 'sg_cachepress_purge_everything' ) ) {
		return;
	}

	// Purge everything on shutdown.
	add_action( 'shutdown', function() {
		sg_cachepress_purge_everything();
	} );
}