diff --git a/core/lib/Drupal/Core/Entity/EntityCreateAccessCheck.php b/core/lib/Drupal/Core/Entity/EntityCreateAccessCheck.php
index 9ceac5249d056271df3dd64eadae999c3bfc153b..b3c12a8da803867e73f099b42413c69ce82641f2 100644
--- a/core/lib/Drupal/Core/Entity/EntityCreateAccessCheck.php
+++ b/core/lib/Drupal/Core/Entity/EntityCreateAccessCheck.php
@@ -62,7 +62,7 @@ public function access(Route $route, RouteMatchInterface $route_match, AccountIn
       }
       // If we were unable to replace all placeholders, deny access.
       if (strpos($bundle, '{') !== FALSE) {
-        return AccessResult::neutral();
+        return AccessResult::neutral(sprintf("Could not find '%s' request argument, therefore cannot check create access.", $bundle));
       }
     }
     return $this->entityManager->getAccessControlHandler($entity_type)->createAccess($bundle, $account, [], TRUE);
diff --git a/core/tests/Drupal/Tests/Core/Entity/EntityCreateAccessCheckTest.php b/core/tests/Drupal/Tests/Core/Entity/EntityCreateAccessCheckTest.php
index 2c3d132cf3c0fd459717498f3ae7e0317ada080b..59f83af029dec25dae3a53884f3c2644c8a5bcc7 100644
--- a/core/tests/Drupal/Tests/Core/Entity/EntityCreateAccessCheckTest.php
+++ b/core/tests/Drupal/Tests/Core/Entity/EntityCreateAccessCheckTest.php
@@ -74,6 +74,9 @@ public function testAccess($entity_bundle, $requirement, $access, $expected, $ex
     if ($expect_permission_context) {
       $expected_access_result->cachePerPermissions();
     }
+    if (!$entity_bundle && !$expect_permission_context) {
+      $expected_access_result->setReason("Could not find '{bundle_argument}' request argument, therefore cannot check create access.");
+    }
 
     $entity_manager = $this->getMock('Drupal\Core\Entity\EntityManagerInterface');