Fatal error: Uncaught Error: Class 'HTMLPurifier_Definition' not found in D:\xampp\htdocs\psp\backend\vendor\ezyang\htmlpurifier\library\HTMLPurifier\CSSDefinition.php:7 Stack trace: #0 {main} thrown in D:\xampp\htdocs\psp\backend\vendor\ezyang\htmlpurifier\library\HTMLPurifier\CSSDefinition.php on line 7