If you suddenly have an error with WooCommerce Email Customizer and your error logs show this issue:
PHP Fatal error: Uncaught Error: Class ‘Emogrifier’ not found in /home/***/public_html/wp-content/plugins/woocommerce-email-control/ec-email-control.php:1068
then the problem occurred as a result of the latest WooCommerce plugin update.
And the solution is as simple as it gets.
Line 1068, replace:
$emogrifier = new Emogrifier( $content, $css );
$emogrifier = new \Pelago\Emogrifier( $content, $css );
Enjoy the fix 🙂