diff -u b/core/modules/media/src/Plugin/Field/FieldWidget/MediaFileWidget.php b/core/modules/media/src/Plugin/Field/FieldWidget/MediaFileWidget.php --- b/core/modules/media/src/Plugin/Field/FieldWidget/MediaFileWidget.php +++ b/core/modules/media/src/Plugin/Field/FieldWidget/MediaFileWidget.php @@ -169,6 +169,9 @@ */ public static function value($element, $input, FormStateInterface $form_state) { $return = parent::value($element, $input, $form_state); + if (empty($return['mids'])) { + $return['mids'] = []; + } $media_type = FALSE; $host_entity = $form_state->getFormObject()->getEntity();