I just upgraded to Drupal 8.6.8 and I have warnings in the terminal when updating the database

I just upgraded to Drupal 8.6.8 and I have warnings in the terminal when updating the database :

ubuntu@www-domaine-com /var/www/www-domaine-com $ drush updatedb
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Creating default object from empty value ModuleHandler.php:236
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Class Drupal\Core\Extension\Extension has no unserializer DatabaseBackend.php:167
 [warning] Creating default object from empty value ModuleHandler.php:236
 [success] No database updates required.