My bank uses client SSL certificates + a single-password token for authentication. Unfortunately, the latest Firefox gives me this error:

Secure Connection Failed

An error occurred during a connection to secure.example.com.

Renegotiation is not allowed on this SSL socket.

(Error code: ssl_error_renegotiation_not_allowed)

The page you are trying to view can not be shown because the authenticity of the received data could not be verified.
Please contact the web site owners to inform them of this problem. Alternatively, use the command found in the help menu to report this broken site.

A workaround, which I do not recommend, as pointed out here, is to set security.ssl.allow_unrestricted_renego_everywhere__temporarily_available_pref from about:config to true.

A more correct solution would be to read up on the decision to disable the feature, and then just add your server to the security.ssl.renego_unrestricted_hosts configuration value instead.