So I'm trying to do the right thing and validate a web page to ensure it's XHTML compliant. Here's the result:
Sorry, I am unable to validate this document because its content type is
text/plain, which is not currently supported by this service.
OK, great. You can't handle text/plain. I'm sorry. So what do you handle? What do I need to do to resolve this?
Unfortunately, this type of error message is quite common. If you can give an error description this specific, it's also possible to give the user instructions on how to avoid the error. The users are your friends -- help them out.