File: //usr/share/php/Symfony/Bundle/TwigBundle/Resources/views/Exception/error.html.twig
<!DOCTYPE html>
<html>
<head>
<meta charset="{{ _charset }}" />
<title>An Error Occurred: {{ status_text }}</title>
<style>
body { background-color: #fff; color: #222; font: 16px/1.5 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif; margin: 0; }
.container { margin: 30px; max-width: 600px; }
h1 { color: #dc3545; font-size: 24px; }
h2 { font-size: 18px; }
</style>
</head>
<body>
<div class="container">
<h1>Oops! An Error Occurred</h1>
<h2>The server returned a "{{ status_code }} {{ status_text }}".</h2>
<p>
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.
</p>
</div>
</body>
</html>