Fatal error: Uncaught Error: Class 'Drupal\Component\Plugin\PluginBase' not found in /var/www/html/tmp/contrib/simple_oauth/src/Plugin/Oauth2GrantBase.php:11 Stack trace: #0 {main} thrown in /var/www/html/tmp/contrib/simple_oauth/src/Plugin/Oauth2GrantBase.php on line 11