Symfony\Component\DependencyInjection\Exception\InvalidArgumentException: The service file "core/core.services.yml" is not valid. in Drupal\Core\DependencyInjection\YamlFileLoader->loadFile() (line 329 of /home/fourcsd/public_html/core/lib/Drupal/Core/DependencyInjection/YamlFileLoader.php).
Drupal\Core\DependencyInjection\YamlFileLoader->loadFile('core/core.services.yml') (Line: 63) Drupal\Core\DependencyInjection\YamlFileLoader->load('core/core.services.yml') (Line: 1277) Drupal\Core\DrupalKernel->compileContainer() (Line: 884) Drupal\Core\DrupalKernel->initializeContainer() (Line: 18) Drupal\Core\Installer\InstallerKernel->initializeContainer() (Line: 466) Drupal\Core\DrupalKernel->boot() (Line: 422) install_begin_request(Object, Array) (Line: 114) install_drupal(Object) (Line: 44)
Symfony\Component\DependencyInjection\Exception\ServiceNotFoundException: You have requested a non-existent service "theme.manager". in Symfony\Component\DependencyInjection\ContainerBuilder->getDefinition() (line 803 of /home/fourcsd/public_html/vendor/symfony/dependency-injection/ContainerBuilder.php).
Symfony\Component\DependencyInjection\ContainerBuilder->getDefinition('theme.manager') (Line: 439) Symfony\Component\DependencyInjection\ContainerBuilder->get('theme.manager') (Line: 674) Drupal::theme() (Line: 22) _drupal_maintenance_theme() (Line: 724) drupal_maintenance_theme() (Line: 971) install_display_output(Array, Array, Array) (Line: 264) _drupal_log_error(Array, 1) (Line: 584) _drupal_exception_handler(Object)