Fatal error: Uncaught Error: Interface "Psr\Log\LoggerInterface" not found in /home/www/drupal8/test/core/lib/Drupal/Core/Logger/LoggerChannelInterface.php:35 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/lib/Drupal/Core/Logger/LoggerChannelInterface.php on line 35