Hi, It looks like you have url's placed in your sitemap that have an HTTP status error. You can search for the urls and remove them from your sitemap or make sure they have the right status. Does it say which status error? And does it say which url's? Did you check those url's?When you use Screaming frog spider tool (free), you can search for status error's this is an easy way to find these url's.
Grtz, Leonie
