I tried to log in from firefox and got the following:
The owner of www.bitcomet.com has configured their web site improperly. To protect your information from being stolen, Firefox has not connected to this web site.
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.
www.bitcomet.com uses an invalid security certificate. The certificate expired on 15 January 2017 07:32. The current time is 15 January 2017 22:18. Error code: SEC_ERROR_EXPIRED_CERTIFICATE
I eventually got in with MS Edge (that's a bit more trusting and allowed me to make an exception)