Fatal Error Class 'Mobile_Detect'

Hello, my site has went down due to the following error, can anyone help me understand what this is? Someone’s help would be very helpful.

Fatal error: Class ‘Mobile_Detect’ not found in /home2/ab76711/public_html/clickliverpool.com/wp-content/plugins/1/includes/embed.php on line 3

<?php

$detect = new Mobile_Detect;
//If this isn't a mobile device add these actions
if (!$detect->isMobile()) {
	add_action('wp_enqueue_scripts','dc_ln_add_scripts');
	add_action('wp_head','dc_ln_wp_head');

Thats the top few lines of code from embed.php