Additional uncaught exception thrown while handling exception.

Original

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)

Additional

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)