Thanks for letsencrypt !
It powers http://hackers.mu/. We are from Mauritius.
However, we have HTST issues with logan.hackers.mu and
On firefox, people get this error:
This site uses HTTP Strict Transport Security (HSTS) to specify that
Firefox only connect to it securely. As a result, it is not possible
to add an exception for this certificate.
Can you please also whitelist the sub-domains ?