Fatal error: Uncaught Error: Class "Drupal\image\ImageEffectBase" not found in /home/www/drupal8/test/core/modules/image/src/Plugin/ImageEffect/DesaturateImageEffect.php:17 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/modules/image/src/Plugin/ImageEffect/DesaturateImageEffect.php on line 17