Fatal error: Uncaught Error: Class "SLN_Enum_CheckoutFields" not found in /var/www/html1/wp-content/plugins/salon-booking-system/views/mail/_custom_fields.php:3 Stack trace: #0 {main} thrown in /var/www/html1/wp-content/plugins/salon-booking-system/views/mail/_custom_fields.php on line 3