XIII
Very Senior Member
Indeed.You can add the exception, but the icon in the address bar still shows as insecure. I think that is what he was referring to.
Apparently Mozilla changed the behavior in Firefox 54:
https://stackoverflow.com/questions/44550970/firefox-54-stopped-trusting-self-signed-certs
This explains why I also saw the problem with 380.66_6 (or any other build if I tried it; 66/67 were probably the only two I tried after I installed Firefox 54).