New Error

I just received a new error. We have had our website running well for the past 6 months. All of a sudden yesterday morning we received this error when trying to view our website. Can anyone tell me what it means? I dont’t know what current version of WordPress we are on. I haven’t updated it since 6 months ago. It also wont let me in the admin login screen. This pops up as well.

<?php
/**
* Front to the WordPress application. This file doesn’t do anything, but loads
* wp-blog-header.php which does and tells WordPress to load the theme.
*
* @package WordPress
*/

/**
* Tells WordPress to load the WordPress theme and output it.
*
* @var bool
*/
define(‘WP_USE_THEMES’, true);

/** Loads the WordPress Environment and Template */
require(‘./leasure/wp-blog-header.php’);