Fatal error: Uncaught Error: Interface "Drupal\Core\Plugin\Context\ContextRepositoryInterface" not found in /home/www/drupal8/test/core/lib/Drupal/Core/Plugin/Context/LazyContextRepository.php:10 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/lib/Drupal/Core/Plugin/Context/LazyContextRepository.php on line 10