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