google is saying the below about our sitemap, is it a cs cart or server issue?
Sitemap has errors
Sitemap is HTML
1 instance

Your Sitemap appears to be an HTML page. Please use a supported sitemap format instead.
Line: 3
Sitemap has errors
Sitemap is HTML
1 instance

Your Sitemap appears to be an HTML page. Please use a supported sitemap format instead.
Line: 3