Issue #3359875 by dcam, tte, geek-merlin, Sophie.SK: Memory allocation error

      // to be referenced otherwise we set the variable to false.

      /** @var \Drupal\Core\Entity\EntityReferenceSelection\SelectionInterface $handler */

      $handler = $this->selectionManager->getInstance($options);

      $have_multiple_existing_entities = $handler->countReferenceableEntities() > 1;

      $have_multiple_existing_entities = count($handler->getReferenceableEntities(NULL, 'CONTAINS', 2)) > 1;

    } else {

      $have_multiple_existing_entities = FALSE;

    }