[Plugin: WordPress SEO by Yoast] Google Webmasters Sitemap Warning

Google Webmaster Tools is giving me an error on this particular sitemap: https://hallowmix.com/product_type-sitemap.xml

Parsing error
We were unable to read your Sitemap. It may contain an entry we are unable to recognize. Please validate your Sitemap before resubmitting.
Line: 4

All of the other sitemaps are working fine.

https://www.ads-software.com/extend/plugins/wordpress-seo/