I just tried it. Got the following message:
What does "Your connection is not secure" mean?
When Firefox connects to a secure website (the URL begins with "https://"), it must verify that the certificate presented by the website is valid and that the encryption is strong enough to adequately protect your privacy. If the certificate cannot be validated or if the encryption is not strong enough, Firefox will stop the connection to the website and instead show an error page:
Fx44 Insecure Connection
I am not 100% sure, but it seems that their SSL certificate has expired. I have an email address for them ... will get off a FYI to them.
Slick