luci/modules/luci-base/luasrc/view/error500.htm

<%#
 Copyright 2008 Steven Barth <steven@midlink.org>
 Copyright 2008 Jo-Philipp Wich <jow@openwrt.org>
 Licensed to the public under the Apache License 2.0.
-%>

<%+header%>
<h2 name="content">500 <%:Internal Server Error%></h2>
<p><%:Sorry, the server encountered an unexpected error.%></p>
<pre class="error500"><%=message%></pre>
<%+footer%>