FireFox does not accept a newly updated {confirmed, valid} certificate (from a new authority) that other browsers accept.
When visitors attempt to access this URL, FireFox warns them that: "remote.edinburgh.gov.uk uses an invalid security certificate. The certificate is not trusted because the issuer certificate is unknown. (Error code: sec_error_unknown_issuer)"
The certificate comes from a different authority than we previously used, and is accepted as valid by IIS / Windows on the parent server, and by all versions of IE that we have tested.
URL of affected sites
Krejt Përgjigjet (3)
The server doesn't send the TERENA SSL CA intermediate certificate. You can check that via http://www.networking4all.com/en/support/tools/site+check/
Thanks, I ended up having to use the DigiCertUtil.exe from https://www.digicert.com/util/ though I still don't know what was actually wrong. Would be really useful if FireFox would give a meaningful error message here - no indication of which of the parent certificates was the problem.
https://remote.edinburgh.gov.uk still gives me the same error, as are several other websites since I upgraded to 3.6.4.