Fatal error: Uncaught Error: Interface 'Composer\Plugin\PluginInterface' not found in /home/eberhardschwarze/public_html/vendor/contao-components/installer/src/Composer/Plugin.php:18 Stack trace: #0 {main} thrown in /home/eberhardschwarze/public_html/vendor/contao-components/installer/src/Composer/Plugin.php on line 18