diff --git a/core/modules/user/src/AccountForm.php b/core/modules/user/src/AccountForm.php
index 602f0e7..8eb4384 100644
--- a/core/modules/user/src/AccountForm.php
+++ b/core/modules/user/src/AccountForm.php
@@ -328,7 +328,9 @@ public function validate(array $form, FormStateInterface $form_state) {
     $account = $this->entity;
     // Validate new or changing username.
     if ($form_state->hasValue('name')) {
-      if ($error = user_validate_name($form_state->getValue('name'))) {
+      // HELP NEEDED: calling user_validate_name() just causes the form to
+      // complain that no username was supplied.
+      if (false && $error = user_validate_name($form_state->getValue('name'))) {
         $form_state->setErrorByName('name', $error);
       }
       // Cast the user ID as an integer. It might have been set to NULL, which
diff --git a/core/vendor/symfony/validator/Symfony/Component/Validator/Validator/RecursiveContextualValidator.php b/core/vendor/symfony/validator/Symfony/Component/Validator/Validator/RecursiveContextualValidator.php
index 2da1887..99a9442 100644
--- a/core/vendor/symfony/validator/Symfony/Component/Validator/Validator/RecursiveContextualValidator.php
+++ b/core/vendor/symfony/validator/Symfony/Component/Validator/Validator/RecursiveContextualValidator.php
@@ -419,7 +419,8 @@ private function validateEachObjectIn($collection, $propertyPath, array $groups,
 
             // Scalar and null values in the collection are ignored
             // (BC with Symfony < 2.5)
-            if (is_object($value)) {
+            // HELP NEEDED: String can't be validated, I think we're recursing one level too far
+            if (is_object($value) && get_class($value) != 'Drupal\Core\TypedData\Plugin\DataType\String') {
                 $this->validateObject(
                     $value,
                     $propertyPath.'['.$key.']',
diff --git a/core/modules/user/src/AccountForm.php b/core/modules/user/src/AccountForm.php
index 8eb4384..602f0e7 100644
--- a/core/modules/user/src/AccountForm.php
+++ b/core/modules/user/src/AccountForm.php
@@ -328,9 +328,7 @@ public function validate(array $form, FormStateInterface $form_state) {
     $account = $this->entity;
     // Validate new or changing username.
     if ($form_state->hasValue('name')) {
-      // HELP NEEDED: calling user_validate_name() just causes the form to
-      // complain that no username was supplied.
-      if (false && $error = user_validate_name($form_state->getValue('name'))) {
+      if ($error = user_validate_name($form_state->getValue('name'))) {
         $form_state->setErrorByName('name', $error);
       }
       // Cast the user ID as an integer. It might have been set to NULL, which
diff --git a/core/modules/user/src/Plugin/Validation/Constraint/UserNameConstraintValidator.php b/core/modules/user/src/Plugin/Validation/Constraint/UserNameConstraintValidator.php
index 12d4fa3..887f50f 100644
--- a/core/modules/user/src/Plugin/Validation/Constraint/UserNameConstraintValidator.php
+++ b/core/modules/user/src/Plugin/Validation/Constraint/UserNameConstraintValidator.php
@@ -20,11 +20,17 @@ class UserNameConstraintValidator extends ConstraintValidator {
    * {@inheritdoc}
    */
   public function validate($items, Constraint $constraint) {
-    if (!isset($items) || !$items->value) {
+    // HELP NEEDED: Why has $items changed from an object
+    // (presumably TypedData\ListInterface) into an array?
+    if (!isset($items)) {
+      $this->context->addViolation($constraint->emptyMessage);
+      return;
+    }
+    $name = is_array($items) ? $items[0]['value'] : $items->first()->value;
+    if (!$name) {
       $this->context->addViolation($constraint->emptyMessage);
       return;
     }
-    $name = $items->first()->value;
     if (substr($name, 0, 1) == ' ') {
       $this->context->addViolation($constraint->spaceBeginMessage);
     }
diff --git a/core/vendor/symfony/validator/Symfony/Component/Validator/Validator/RecursiveContextualValidator.php b/core/vendor/symfony/validator/Symfony/Component/Validator/Validator/RecursiveContextualValidator.php
index 99a9442..c1cfbb5 100644
--- a/core/vendor/symfony/validator/Symfony/Component/Validator/Validator/RecursiveContextualValidator.php
+++ b/core/vendor/symfony/validator/Symfony/Component/Validator/Validator/RecursiveContextualValidator.php
@@ -420,7 +420,7 @@ private function validateEachObjectIn($collection, $propertyPath, array $groups,
             // Scalar and null values in the collection are ignored
             // (BC with Symfony < 2.5)
             // HELP NEEDED: String can't be validated, I think we're recursing one level too far
-            if (is_object($value) && get_class($value) != 'Drupal\Core\TypedData\Plugin\DataType\String') {
+            if (is_object($value) && ($value instanceof \Drupal\Core\TypedData\ComplexDataInterface || $value instanceof \Drupal\Core\TypedData\ListInterface)) {
                 $this->validateObject(
                     $value,
                     $propertyPath.'['.$key.']',