Unable to install Let's Encrypt SSL

root@Dhruba:~# ee site update website name --letsencrypt
Letsencrypt is currently in beta phase.
Do you wish to enable SSl now for website name?
Type “y” to continue [n]:y
Please Wait while we fetch SSL Certificate for your site.
It may take time depending upon network.
Unable to setup, Let’s Encrypt
Please make sure that your site is pointed to
same server on which you are running Let’s Encrypt Client
to allow it to verify the site automatically.

My website is pointed to the correct server IP address.