Fatal error: Uncaught Error: Class 'HTMLPurifier_AttrDef_CSS_Number' not found in D:\xampp\htdocs\psp\backend\vendor\ezyang\htmlpurifier\library\HTMLPurifier\AttrDef\CSS\AlphaValue.php:3 Stack trace: #0 {main} thrown in D:\xampp\htdocs\psp\backend\vendor\ezyang\htmlpurifier\library\HTMLPurifier\AttrDef\CSS\AlphaValue.php on line 3