doctype html html(lang="de") head title= "500 - Internal Server Error" meta(charset="UTF-8") meta(name="viewport", content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no") link(rel="stylesheet", type="text/css", href="/css/bootstrap.min.css") style. .container { height: 400px; position: relative; } .center { margin: 0; position: absolute; top: 50%; left: 50%; -ms-transform: translate(-50%, -50%); transform: translate(-50%, -50%); } body div(class="container") div(class="center", align="center") a(href="https://m4lab.hft-stuttgart.de") img(src="https://transfer.hft-stuttgart.de/images/demo/m4lab_logo.jpg", class="img-responsive center-block", width="185", height="192") br br p(class="h5") 500. Unexpected Error :( p #{ error } // Bootstrap script(src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js" integrity="sha384-JjSmVgyd0p3pXB1rRibZUAYoIIy6OrQ6VrjIEaFf/nJGzIxFDsf4x0xIM+B07jRM" crossorigin="anonymous")