Fatal error: Uncaught Error: Class "Negotiation\AbstractNegotiator" not found in /home/flighto/e-commerce/vendor/willdurand/negotiation/src/Negotiation/EncodingNegotiator.php:5 Stack trace: #0 {main} thrown in /home/flighto/e-commerce/vendor/willdurand/negotiation/src/Negotiation/EncodingNegotiator.php on line 5