Fatal error: Uncaught Error: Class 'Braintree\Exception' not found in /home/app/htdocs/ninja/vendor/braintree/braintree_php/lib/Braintree/Exception/InvalidSignature.php:6 Stack trace: #0 {main} thrown in /home/app/htdocs/ninja/vendor/braintree/braintree_php/lib/Braintree/Exception/InvalidSignature.php on line 6