Reason for "Non-document error"? from Mike Elledge on 2016-06-15 (www-validator@w3.org from June 2016)

From: Mike Elledge <melledge@yahoo.com>
Date: Wed, 15 Jun 2016 20:40:07 +0000 (UTC)
To: "www-validator@w3.org" <www-validator@w3.org>
Message-ID: <77189138.3848307.1466023207536.JavaMail.yahoo@mail.yahoo.com>

Hi All--
I have a local instance of the Nu HTML checker installed on my computer and have no problems when I validate a local file. When I attempt to validate a website, however, I get a "Non-Document Error" message.
I looked through the documentation but couldn't find an explanation. Any thoughts for why this is happening?
Thanks.
Mike Elledge

Received on Wednesday, 15 June 2016 20:43:35 UTC