Fatal error: Uncaught Error: Interface 'Http\Client\Common\Plugin' not found in /home/eberhardschwarze/public_html/vendor/php-http/client-common/src/Plugin/HeaderAppendPlugin.php:19 Stack trace: #0 {main} thrown in /home/eberhardschwarze/public_html/vendor/php-http/client-common/src/Plugin/HeaderAppendPlugin.php on line 19