Fatal error: Uncaught Error: Class "League\Fractal\Serializer\SerializerAbstract" not found in D:\programs\xampp\htdocs\backend-test\vendor\league\fractal\src\Serializer\ArraySerializer.php:18 Stack trace: #0 {main} thrown in D:\programs\xampp\htdocs\backend-test\vendor\league\fractal\src\Serializer\ArraySerializer.php on line 18