Sapete che errore è questo:

Sorry, I am unable to validate this document because its content type is text/plain, which is not currently supported by this service.

The Content-Type field is sent by your web server (or web browser if you use the file upload interface) and depends on its configuration. Commonly, web servers will have a mapping of filename extensions (such as ".html") to MIME Content-Type values (such as text/html).


con il validatore del w3c