Edit File: Set.php
<?php use Twig\Node\SetNode; class_exists('Twig\Node\SetNode'); @trigger_error(sprintf('Using the "Twig_Node_Set" class is deprecated since Twig version 2.7, use "Twig\Node\SetNode" instead.'), E_USER_DEPRECATED); if (\false) { /** @deprecated since Twig 2.7, use "Twig\Node\SetNode" instead */ class Twig_Node_Set extends SetNode { } }