Issue with SSL Certificates (Apache / Ubuntu)

I've followed the guides for setting an SSL Certificate with Apache on Ubuntu with an a Self-Signed Certificate

1 - https://www.linode.com/docs/security/ss … ian-ubuntu">https://www.linode.com/docs/security/ssl/ssl-apache2-debian-ubuntu

2 - https://www.linode.com/docs/security/ss … and-ubuntu">https://www.linode.com/docs/security/ssl/create-a-self-signed-certificate-on-debian-and-ubuntu

Everything appears to have gone well and is setup correctly however when i try to access the site securely the page does not load and returns a "Failed to open page - because the server where this page is located isn’t responding." error.

I've run openssl s_client -CApath /etc/ssl/certs/ -connect mydomain.com:443 and it returns the certificate with no errors.

I'm not sure what other steps i can take to debug this issue.

Caveat - I originally setup a separate certificate for another domain but it is not enabled in that domains .conf file. Could this be an issue? Is it possible to have multiple certificates for each domain?