Warning: Unsupported declare 'strict_types' in D:\xampp\htdocs\prdk-wb-be\vendor\guzzlehttp\promises\src\AggregateException.php on line 3

Fatal error: Class 'GuzzleHttp\Promise\RejectionException' not found in D:\xampp\htdocs\prdk-wb-be\vendor\guzzlehttp\promises\src\AggregateException.php on line 11