Fatal error: Uncaught Error: Class "Respect\Validation\Rules\AbstractEnvelope" not found in C:\xampp\htdocs\vendor\respect\validation\library\Rules\HexRgbColor.php:18 Stack trace: #0 {main} thrown in C:\xampp\htdocs\vendor\respect\validation\library\Rules\HexRgbColor.php on line 18