Issue #3072733 by ygerasimov: Notice in ElasticsearchViewsMarkup

modules/elasticsearch_connector_views/src/Plugin/views/field/ElasticsearchViewsMarkup.php

@@ -3,6 +3,8 @@
 namespace Drupal\elasticsearch_connector_views\Plugin\views\field;
 
 use Drupal\views\Plugin\views\field\Markup;
+use Drupal\views\Plugin\views\display\DisplayPluginBase;
+use Drupal\views\ViewExecutable;
 
 /**
  * Provides a default handler for fields in Search API Views.
@@ -13,4 +15,14 @@ use Drupal\views\Plugin\views\field\Markup;
  */
 class ElasticsearchViewsMarkup extends Markup {
 
+  /**
+  * {@inheritdoc}
+  */
+  public function init(ViewExecutable $view, DisplayPluginBase $display, array &$options = NULL) {
+    if (!isset($this->definition['format'])) {
+      $this->definition['format'] = filter_default_format();
+    }
+    parent::init($view, $display, $options);
+  }
+
 }