FrontBundle/Resources/views/Exception/error.fragment.html.twig
<h1>Oops! An Error Occurred</h1>
<h2>The server returned a "{{ status_code }} {{ status_text }}".</h2>
<div>
Something is broken. Please let us know what you were doing when this error occurred.
We will fix it as soon as possible. Sorry for any inconvenience caused.
</div>