View file phpBB3/vendor/twig/twig/lib/Twig/Error.php

<?php

use Twig\Error\Error;

class_exists('Twig\Error\Error');

@trigger_error('Using the "Twig_Error" class is deprecated since Twig version 2.7, use "Twig\Error\Error" instead.', \E_USER_DEPRECATED);

if (false) {
    /** @deprecated since Twig 2.7, use "Twig\Error\Error" instead */
    class Twig_Error extends Error
    {
    }
}