Cloner creates a blank site

Hi there

I would like to clone my main site to create 2 subdomains i.e. subdomain1.mywebsite.com and subdomain2.mywebsite.com. Currently when I clone the site in Cloner, it creates a blank site that takes me to an error page in my browser.

Please can you assist urgently. I have granted access.

Many thanks
Ashleigh