Empty Sitemap

facing an issue with the sitemap “sitemap-tax-post_tag.xml”

Type: Errors
Issue:Empty Sitemap
Description: Your Sitemap does not contain any URLs. Please validate and resubmit your Sitemap.

After Resubmitting and validating, issue still exist..

it shows the message like ” This XML file does not appear to have any style information associated with it. The document tree is shown below.”

while all others are working fine, Only error exist with TAGS.

Please guide and help;

http://www.pakistanidramaa.com/sitemap.xml

https://wordpress.org/plugins/google-sitemap-generator/