Why sitemap fails

Possible reasons why the sitemap might be flagged as Unhealthy or PRD fails to crawl them:

• The Sitemap URL is incorrect
  • Please double check the Sitemaps URL
• Our crawler might be blocked by a firewall
  • Check if your firewall might be blocking our IP addresses or user agents and Whitelist the IP addresses and the user agents if necessary. 
• The Sitemap does not follow the template of https://sitemaps.org/protocol.html
  • Check the sitemap structure and syntax
• One or multiple URLs on the Sitemap throw a non-200 HTTP status. For example, 404, one of the URLs does not exist. 
  • Check the URLs in the list if they return a 200 status. 

Related articles: 

- How to Use Prerender's Sitemap Crawler

- How to crawl and render pages only from our xml sitemap

- Overview of Prerender.io Crawlers