Fatal error: Uncaught Error: Class 'League\Fractal\Serializer\SerializerAbstract' not found in /home/app/htdocs/ninja/vendor/league/fractal/src/Serializer/ArraySerializer.php:18 Stack trace: #0 {main} thrown in /home/app/htdocs/ninja/vendor/league/fractal/src/Serializer/ArraySerializer.php on line 18