/author-sitemap.xml

[focus]

In Google Webmaster Tools I'm having an error with /author-sitemap.xml is this very important since I already have a /page-sitemap.xml?

The error I get from the Author Sitemap is:
"Your Sitemap appears to be an HTML page. Please use a supported sitemap format instead."

 

[intlx10m]

Have a look at https://support.google.com/webmasters/answer/35738?hl=en . Looks like you have messed up XML. When it comes to writing code even a single mistake costs a lot. If you are not familiar with XML go on with http://www.xml-sitemaps.com/ it automatically scans up your website and makes a XML file. After that you can either customize it or just let it as it is.

 

[focus]

I'm using Yoast SEO Plugin shouldn't this be done automatically? Did i miss something?