Blank Page on Sitemap with W3TC

Hi,
I was trying to fix this from a long time. I have done all kind of research but didnt find any appropriate answers.
this is my sitemap link: http://www.isaumya.com/sitemap_index.xml
whenever i turn off W3TC, it starts working again. But I cant W3TC right now, cause it handels my cdn. So, can u please help?

https://wordpress.org/plugins/wordpress-seo/