Hi, just answered you by email please use email address for further communication.
Post here the answer useful for other users encountering the same issue.
QUOTE:
this problem is not related directly to the sitemap component.
Normally this problem happens when there is a plugin or server settings that replaces all links from http:// to https://
So i guess that your site runs on https:// protocol and the Joomla output including the sitemap has all links replaced.
As a result the correct link: http://www.sitemaps.org/schemas/sitemap/0.9
is replaced with https://www.sitemaps.org/schemas/sitemap/0.9
thus invalidating the XML document.
The plugin forcing https everywhere commonly is Admin Tools so try to rule it.
Thanks and best regards
John Dagelmore
