sitemap.xml parses as urlset or sitemapindex
A sitemap that doesn't parse is functionally identical to no sitemap at all. This check catches the very common case of a sitemap.xml served with the wrong root element or malformed XML.
How the check decides
The check parses the sitemap body with fast-xml-parser and inspects the root element. Passes if the parsed tree has a <urlset> (a regular sitemap) or <sitemapindex> (a sitemap index that points at child sitemaps) at its root. Fails if the body isn’t valid XML or has neither root element. Returns N/A if no sitemap was found at all.
How to implement it
Use a known-good sitemap generator rather than templating XML by hand. If you’re hand-rolling, double-check namespace declarations and ensure the root element is <urlset> or <sitemapindex>.
Pass
<?xml version="1.0" encoding="UTF-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
<url><loc>https://example.com/</loc></url>
</urlset>
Fail
<?xml version="1.0" encoding="UTF-8"?>
<pages>
<page>https://example.com/</page>
</pages>