Why twig error template doesn't see routes?

Question

symfony

Created a template for displaying errors on the site

app/Resources/TwigBundle/views/Exception/error.html.twig

{% extends 'base.html.twig' %}

{% block main %}
    <div class="content">
        <div class="wrap">
            
        </div>
    </div>
{% endblock %}

But it doesn't work. There is always an error in the logs
Unable to generate a URL for the named route ...
Although there is no error on normal pages.
Why is that?