This is actually not an issue you may be able to fix, the reason is because most Wordpress themes by default don't have author information or dates within your PAGES on your website...but they do within your posts.

Most people do get this error at some point within their Google Webmaster tools and although it looks bad, it won't really impact your rankings. As you build out your website you will be creating "posts" not pages after your initial framework is built out.

You are going to be just fine here Amanda, not anything to be overly concerned about. I have these same errors on some of my websites and they outrank some of the most popular news sites on the Internet all the time (1st page and 1st overall rankings).

Just found the same problem too today. I don't have to worry then.. Thanks Kyle

I have this on the end of my sitemap /index.php?xml_sitemap=params and no info yet on site after two days...? Can anyone help please...