Freelance Project

I have a SSL certificate but the secure version of my site is not loading properly WHEN FIREFOX IS USED AS THE Internet Connection.

The exact error I am getting is the following:

www.kicksbay.com uses an invalid security certificate.
The certificate is not trusted because the issuer certificate is unknown.
(Error code: sec_error_unknown_issuer)

When communicating with my hosting company they said the following:

The only error I’m currently getting is the partially encrypted content one, which is because you still have a few things linking to the HTTP URL (I saw http://www.kicksbay.com/style.css but there may be others). Please let us know if you’re still having trouble.

I need someone to fix the issue so that my secure connection works in FireFox.

Thanks.