Have always been a fan of the Yoast plugin! But have found this problem also after noticing the error at Google Webmaster Tools.
Our posts-sitemap (http://www.fluxmagazine.com/index.php/post-sitemap.xml) is empty/blank.
The others generated at the same time are fine, eg. http://www.fluxmagazine.com/index.php/category-sitemap.xml
I have tried regenerating by updating a post and doesn’t resolve.
Any support most welcome 🙂
I have the identical issue to you colinmarney with the empty DM Albums widget. Did you ever resolve??
Thanks.
Claire.
