Some browsers may be showing this as of the last hour. Known and is in work. Will update when resolved.
This is now resolved. Apologies for any inconvenience!
I got a certificate issue today using Firefox 56.0.1 on Windows 10. Could not access NSF. I was getting the error "ssl_error_no_cypher_overlap".Followed the instructions here to be able to access NSF, but that's far from ideal : https://www.ryananddebi.com/2014/12/10/bypassing-the-ssl_error_no_cypher_overlap-error-in-firefox-34/