Error after updating Webform from 8.x-5.0-beta15 to 8.x-5.0-rc1 A Drupal 8 site hosted on Pantheon gives this error message after updating Webform from 8.x-5.0-beta15 to 8.x-5.0-rc1: 

The website encountered an unexpected error. Please try again later.
TypeError: Argument 1 passed to Drupal\webform\WebformTokenManager::__construct() must implement interface Drupal\Core\Config\ConfigFactoryInterface, instance of Drupal\Core\Extension\ModuleHandler given, called in /srv/bindings/261ff5c4a9e04814be06a20de36ae33a/code/core/lib/Drupal/Component/DependencyInjection/Container.php on line 266 in Drupal\webform\WebformTokenManager->__construct() (line 46 of modules/webform/src/WebformTokenManager.php).

The site is completely down at that point and we have to revert to a backup.
Any suggestions?
Yes, flushing the cache via Drush should solve the problem. 

If you can't use Drush, you must put your site in maintenance mode, set $update_free_access=TRUE, and run the pending updates via /update.php. 

Also see 

http://www.zymphonies.com/blog/update-drupal8-core
https://www.drupal.org/project/webform/issues/2907960