Warning: Class "Drupal\Core\Http\KernelEvent" not found in /home/ceprvox_live/drupal/web/core/includes/bootstrap.inc on line 135

Fatal error: Uncaught Error: Class "Drupal\Core\Installer\InstallerKernel" not found in /home/ceprvox_live/drupal/web/core/includes/errors.inc:315 Stack trace: #0 /home/ceprvox_live/drupal/web/core/includes/errors.inc(123): _drupal_get_error_level() #1 /home/ceprvox_live/drupal/web/core/includes/bootstrap.inc(385): error_displayable() #2 /home/ceprvox_live/drupal/web/core/includes/bootstrap.inc(369): _drupal_exception_handler_additional(Object(Error), Object(Error)) #3 [internal function]: _drupal_exception_handler(Object(Error)) #4 {main} thrown in /home/ceprvox_live/drupal/web/core/includes/errors.inc on line 315