In DevTest, I am getting an error on just a few URLs out of thousands where the error is "Public" needs to end with '>'. <!DOCTYPE PUBLIC "-//W3C/DTD XHTML 1.0 Transition/EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> There is a '>' at the end of the tag."
The responses from the few URLs that fails in DevTest are dying because the first line of the response contains <?xml version="1.0" encoding="UTF-8" standalone="Yes"?>. After this there is all HTML, so the XML parser is getting invoked to do HTML parsing and it is dying because it was not intended to do that kind of parsing.
All supported DevTest Components
Verify that the HTML response page contains HTML responses and tags and not mis-match of XML and HTML