diff -u b/core/modules/edit/lib/Drupal/edit/EditController.php b/core/modules/edit/lib/Drupal/edit/EditController.php
--- b/core/modules/edit/lib/Drupal/edit/EditController.php
+++ b/core/modules/edit/lib/Drupal/edit/EditController.php
@@ -134,7 +134,7 @@
       }
 
       // Validate the field name and language.
-      if (!$field_name || || !$entity->getPropertyDefinition($field_name)) {
+      if (!$field_name || !$entity->getPropertyDefinition($field_name)) {
         throw new NotFoundHttpException();
       }
       if (!$langcode || (field_valid_language($langcode) !== $langcode)) {