Fatal error: Uncaught Error: Interface 'Contao\ManagerPlugin\Config\ConfigPluginInterface' not found in /home/eberhardschwarze/public_html/vendor/contao/manager-plugin/tests/Fixtures/PluginLoader/FooConfigPlugin.php:8 Stack trace: #0 {main} thrown in /home/eberhardschwarze/public_html/vendor/contao/manager-plugin/tests/Fixtures/PluginLoader/FooConfigPlugin.php on line 8