Fatal error: Uncaught Error: Class 'Whoops\Handler\Handler' not found in D:\xampp\htdocs\psp\backend\vendor\filp\whoops\src\Whoops\Handler\CallbackHandler.php:16 Stack trace: #0 {main} thrown in D:\xampp\htdocs\psp\backend\vendor\filp\whoops\src\Whoops\Handler\CallbackHandler.php on line 16