Cloudflare blocking iframes

Hi,

I use fancybox to open some pages by iframe from a subdomain of my main domain. Cloudflare is blocking these requests. How can i allow maindomain to open pages by iframe from my subdomain ?

I am getting this error message in chrome inspector.

Refused to display ‘domain’ in a frame because it set ‘X-Frame-Options’ to ‘sameorigin’.