What does this report contain?
Sitemaps included in the crawl which return a broken status code (400, 404, 410, 500, or 501) or are disallowed by the robots.txt file.
How can this report be used?
Sitemaps must be crawlable and return a 200 status in order to be processed. This report contains a list of sitemaps that return an HTTP status code 400 or higher, meaning that an error occurred when they were crawled, or which we were not able to crawl because they were blocked by your robots.txt file.