diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/EntityReferenceAutocompleteWidget.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/EntityReferenceAutocompleteWidget.php
index 948079e..4cdbcb9 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/EntityReferenceAutocompleteWidget.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/EntityReferenceAutocompleteWidget.php
@@ -119,7 +119,7 @@ public function formElement(FieldItemListInterface $items, $delta, array $elemen
   /**
    * {@inheritdoc}
    */
-  public function errorElement(array $element, ConstraintViolationInterface $error, array $form, FormStateInterface $form_state) {
+  public function errorElement(array $element, array $property_path, ConstraintViolationInterface $violation, array $form, FormStateInterface $form_state) {
     return $element['target_id'];
   }
 
diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/NumberWidget.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/NumberWidget.php
index 50f8006..d845a4d 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/NumberWidget.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/NumberWidget.php
@@ -114,7 +114,7 @@ public function formElement(FieldItemListInterface $items, $delta, array $elemen
   /**
    * {@inheritdoc}
    */
-  public function errorElement(array $element, ConstraintViolationInterface $violation, array $form, FormStateInterface $form_state) {
+  public function errorElement(array $element, array $property_path, ConstraintViolationInterface $violation, array $form, FormStateInterface $form_state) {
     return $element['value'];
   }
 
diff --git a/core/lib/Drupal/Core/Field/WidgetBase.php b/core/lib/Drupal/Core/Field/WidgetBase.php
index 356eece..41a2cb9 100644
--- a/core/lib/Drupal/Core/Field/WidgetBase.php
+++ b/core/lib/Drupal/Core/Field/WidgetBase.php
@@ -426,7 +426,7 @@ public function flagErrors(FieldItemListInterface $items, ConstraintViolationLis
           $property_path = explode('.', $violation->getPropertyPath());
           $delta = array_shift($property_path);
           $violations_by_delta[$delta][] = $violation;
-          $violation->arrayPropertyPath = $property_path;
+          $violation->arrayPropertyPath = array_filter($property_path);
         }
 
         /** @var \Symfony\Component\Validator\ConstraintViolationInterface[] $delta_violations */
@@ -443,8 +443,9 @@ public function flagErrors(FieldItemListInterface $items, ConstraintViolationLis
             $delta_element = $element[$original_delta];
           }
           foreach ($delta_violations as $violation) {
-            // @todo: Pass $violation->arrayPropertyPath as property path.
-            $error_element = $this->errorElement($delta_element, $violation, $form, $form_state);
+            $property_path = $violation->arrayPropertyPath;
+            unset($violation->arrayPropertyPath);
+            $error_element = $this->errorElement($delta_element, $property_path, $violation, $form, $form_state);
             if ($error_element !== FALSE) {
               $form_state->setError($error_element, $violation->getMessage());
             }
@@ -503,8 +504,8 @@ public function settingsSummary() {
   /**
    * {@inheritdoc}
    */
-  public function errorElement(array $element, ConstraintViolationInterface $error, array $form, FormStateInterface $form_state) {
-    return $element;
+  public function errorElement(array $element, array $property_path, ConstraintViolationInterface $error, array $form, FormStateInterface $form_state) {
+    return NestedArray::getValue($element, $property_path);
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Field/WidgetInterface.php b/core/lib/Drupal/Core/Field/WidgetInterface.php
index 39f7cc4..6022f05 100644
--- a/core/lib/Drupal/Core/Field/WidgetInterface.php
+++ b/core/lib/Drupal/Core/Field/WidgetInterface.php
@@ -117,6 +117,8 @@ public function formElement(FieldItemListInterface $items, $delta, array $elemen
    * @param array $element
    *   An array containing the form element for the widget, as generated by
    *   formElement().
+   * @param array $property_path
+   *   An array containing the path to the flagged sub-element.
    * @param \Symfony\Component\Validator\ConstraintViolationInterface $violation
    *   A constraint violation reported during the validation phase.
    * @param array $form
@@ -129,7 +131,7 @@ public function formElement(FieldItemListInterface $items, $delta, array $elemen
    *   The element on which the error should be flagged, or FALSE to completely
    *   ignore the violation (use with care!).
    */
-  public function errorElement(array $element, ConstraintViolationInterface $violation, array $form, FormStateInterface $form_state);
+  public function errorElement(array $element, array $property_path, ConstraintViolationInterface $violation, array $form, FormStateInterface $form_state);
 
   /**
    * Massages the form values into the format expected for field values.
diff --git a/core/modules/field/tests/modules/field_test/src/Plugin/Field/FieldWidget/TestFieldWidget.php b/core/modules/field/tests/modules/field_test/src/Plugin/Field/FieldWidget/TestFieldWidget.php
index b90008a..9580daf 100644
--- a/core/modules/field/tests/modules/field_test/src/Plugin/Field/FieldWidget/TestFieldWidget.php
+++ b/core/modules/field/tests/modules/field_test/src/Plugin/Field/FieldWidget/TestFieldWidget.php
@@ -74,7 +74,7 @@ public function formElement(FieldItemListInterface $items, $delta, array $elemen
   /**
    * {@inheritdoc}
    */
-  public function errorElement(array $element, ConstraintViolationInterface $violation, array $form, FormStateInterface $form_state) {
+  public function errorElement(array $element, array $property_path, ConstraintViolationInterface $error, array $form, FormStateInterface $form_state) {
     return $element['value'];
   }
 
diff --git a/core/modules/field/tests/modules/field_test/src/Plugin/Field/FieldWidget/TestFieldWidgetMultiple.php b/core/modules/field/tests/modules/field_test/src/Plugin/Field/FieldWidget/TestFieldWidgetMultiple.php
index ed43782..1d241f7 100644
--- a/core/modules/field/tests/modules/field_test/src/Plugin/Field/FieldWidget/TestFieldWidgetMultiple.php
+++ b/core/modules/field/tests/modules/field_test/src/Plugin/Field/FieldWidget/TestFieldWidgetMultiple.php
@@ -81,7 +81,7 @@ public function formElement(FieldItemListInterface $items, $delta, array $elemen
   /**
    * {@inheritdoc}
    */
-  public function errorElement(array $element, ConstraintViolationInterface $violation, array $form, FormStateInterface $form_state) {
+  public function errorElement(array $element, array $property_path, ConstraintViolationInterface $error, array $form, FormStateInterface $form_state) {
     return $element;
   }
 
diff --git a/core/modules/path/src/Plugin/Field/FieldWidget/PathWidget.php b/core/modules/path/src/Plugin/Field/FieldWidget/PathWidget.php
index 07f1712..300a001 100644
--- a/core/modules/path/src/Plugin/Field/FieldWidget/PathWidget.php
+++ b/core/modules/path/src/Plugin/Field/FieldWidget/PathWidget.php
@@ -104,7 +104,7 @@ public static function validateFormElement(array &$element, FormStateInterface $
   /**
    * {@inheritdoc}
    */
-  public function errorElement(array $element, ConstraintViolationInterface $violation, array $form, FormStateInterface $form_state) {
+  public function errorElement(array $element, array $property_path, ConstraintViolationInterface $error, array $form, FormStateInterface $form_state) {
     return $element['alias'];
   }
 
diff --git a/core/modules/text/src/Plugin/Field/FieldWidget/TextareaWidget.php b/core/modules/text/src/Plugin/Field/FieldWidget/TextareaWidget.php
index 0ac3151..b5ee67a 100644
--- a/core/modules/text/src/Plugin/Field/FieldWidget/TextareaWidget.php
+++ b/core/modules/text/src/Plugin/Field/FieldWidget/TextareaWidget.php
@@ -41,8 +41,8 @@ public function formElement(FieldItemListInterface $items, $delta, array $elemen
   /**
    * {@inheritdoc}
    */
-  public function errorElement(array $element, ConstraintViolationInterface $violation, array $form, FormStateInterface $form_state) {
-    if ($violation->arrayPropertyPath == array('format') && isset($element['format']['#access']) && !$element['format']['#access']) {
+  public function errorElement(array $element, array $property_path, ConstraintViolationInterface $error, array $form, FormStateInterface $form_state) {
+    if ($property_path == ['format'] && isset($element['format']['#access']) && !$element['format']['#access']) {
       // Ignore validation errors for formats if formats may not be changed,
       // i.e. when existing formats become invalid. See filter_process_format().
       return FALSE;
diff --git a/core/modules/text/src/Plugin/Field/FieldWidget/TextareaWithSummaryWidget.php b/core/modules/text/src/Plugin/Field/FieldWidget/TextareaWithSummaryWidget.php
index c6bef4f..27954fa 100644
--- a/core/modules/text/src/Plugin/Field/FieldWidget/TextareaWithSummaryWidget.php
+++ b/core/modules/text/src/Plugin/Field/FieldWidget/TextareaWithSummaryWidget.php
@@ -90,9 +90,9 @@ function formElement(FieldItemListInterface $items, $delta, array $element, arra
   /**
    * {@inheritdoc}
    */
-  public function errorElement(array $element, ConstraintViolationInterface $violation, array $form, FormStateInterface $form_state) {
+  public function errorElement(array $element, array $property_path, ConstraintViolationInterface $error, array $form, FormStateInterface $form_state) {
     $element = parent::errorElement($element, $violation, $form, $form_state);
-    return ($element === FALSE) ? FALSE : $element[$violation->arrayPropertyPath[0]];
+    return ($element === FALSE) ? FALSE : $element[$property_path[0]];
   }
 
 }
diff --git a/core/modules/text/src/Plugin/Field/FieldWidget/TextfieldWidget.php b/core/modules/text/src/Plugin/Field/FieldWidget/TextfieldWidget.php
index ab2f19a..4bf6b90 100644
--- a/core/modules/text/src/Plugin/Field/FieldWidget/TextfieldWidget.php
+++ b/core/modules/text/src/Plugin/Field/FieldWidget/TextfieldWidget.php
@@ -41,8 +41,8 @@ public function formElement(FieldItemListInterface $items, $delta, array $elemen
   /**
    * {@inheritdoc}
    */
-  public function errorElement(array $element, ConstraintViolationInterface $violation, array $form, FormStateInterface $form_state) {
-    if ($violation->arrayPropertyPath == array('format') && isset($element['format']['#access']) && !$element['format']['#access']) {
+  public function errorElement(array $element, array $property_path, ConstraintViolationInterface $error, array $form, FormStateInterface $form_state) {
+    if ($property_path == ['format'] && isset($element['format']['#access']) && !$element['format']['#access']) {
       // Ignore validation errors for formats if formats may not be changed,
       // i.e. when existing formats become invalid. See filter_process_format().
       return FALSE;