Fatal error: Uncaught Error: Interface "Composer\Plugin\PluginInterface" not found in /home/vincent/http/concrete5/concrete/vendor/wikimedia/composer-merge-plugin/src/MergePlugin.php:82 Stack trace: #0 {main} thrown in /home/vincent/http/concrete5/concrete/vendor/wikimedia/composer-merge-plugin/src/MergePlugin.php on line 82