W3Validation shows 'end of document in prolog' Error

Question

I am trying to validate my website in http://validator.w3.org/ but error is showing as follows:

Line 1, Column 1: end of document in prolog ✉ This error may appear when the validator receives an empty document. Please make sure that the document you are uploading is not empty, and report any discrepancy.

Here is the link:

http://validator.w3.org/check?uri=www.lab5connect.com&charset=%28detect+automatically%29&doctype=Inline&group=0

Answer 1

Your server seems to send HTTP error 500 when requesting this page:

curl -I http://www.lab5connect.com/ has the following result:

HTTP/1.1 500 Internal Server Error
Cache-Control: private
Content-Length: 3420
Content-Type: text/html; charset=utf-8
Server: Microsoft-IIS/7.0
X-AspNet-Version: 4.0.30319
X-Powered-By: ASP.NET
Date: Thu, 05 Sep 2013 20:10:48 GMT

You should send 200 instead.

Quick workaround: copy the HTML and paste into the Validate by Direct Input field.

Answer 2

Good answer above - additonal information... I'm building a new site and got this error too. My problem was resolved by removing references in my .htaccess file for custom error pages which don't yet exist. They were there as I borrowed the access file from another website which I've already developed.

example:

ErrorDocument 100 /100.shtml
ErrorDocument 101 /101.shtml
ErrorDocument 102 /102.shtml
ErrorDocument 200 /200.shtml
# etc.

Once these lines were removed, the page validated as XHTML 1.0 Strict.