drupal 8.2 to 8.5 update error I am getting the following error.


  Recoverable fatal error: Argument 3 passed to
  Drupal\page_manager\Routing\VariantRouteFilter::__construct() must be
  an instance of Symfony\Component\HttpFoundation\RequestStack, none
  given, called in
  /home/ranjith/public_html/core/lib/Drupal/Component/DependencyInjection/Container.php
  on line 266 and defined in
  Drupal\page_manager\Routing\VariantRouteFilter->__construct() (line 64
  of
  sites/all/modules/contrib/page_manager/src/Routing/VariantRouteFilter.php).


What does it mean? How can I fix that error?
What you're seeing is the result of the Drupal service container failing to create a service because its cached definition doesn't match the class anymore: An extra constructor argument was added (in this change), and Drupal is not passing that argument.

This is a typical error that can happen after updating modules. Make sure to completely empty your cache manually. You might be able to do this using drupal cr all or drush cr or by visiting the admin backend, but not if the service is already loaded during bootstrap. In that case, try to empty the cache_container database table directly.