W3C Semantic Data Extractor - looks not working anymore (?)

Hello

I'm trying to check the semantic of some websites they have always worked
with this

https://www.w3.org/2003/12/semantic-extractor

but now with all of them I get this message

Using org.apache.xerces.parsers.SAXParser
Exception net.sf.saxon.trans.XPathException: org.xml.sax.SAXParseException;
systemId:
http://services.w3.org/tidy/tidy?docAddr=http%3A%2F%2Fwww.recupero-dati-nas-raid5.it&passThroughXHTML=1;
lineNumber: 1; columnNumber: 3; The markup in the document preceding the
root element must be well-formed.
org.xml.sax.SAXParseException; systemId:
http://services.w3.org/tidy/tidy?docAddr=http%3A%2F%2Fwww.recupero-dati-nas-raid5.it&passThroughXHTML=1;
lineNumber: 1; columnNumber: 3; The markup in the document preceding the
root element must be well-formed.

I tried your same link https://www.w3.org/2003/12/semantic-extractor same
exception

just to let you know

Thank you

Roberto