Fatal error: Uncaught Error: Class "Braintree\Exception" not found in /var/www/develop/www/php/vendor/braintree/braintree_php/lib/Braintree/Exception/InvalidSignature.php:6 Stack trace: #0 {main} thrown in /var/www/develop/www/php/vendor/braintree/braintree_php/lib/Braintree/Exception/InvalidSignature.php on line 6