Firefox версий 31-33 имели баг, запрещающий использовать самоподписанные сертификаты. Причем его исправили только со второй попытки, поэтому в 3 версиях он присутствовал как fixed.
Решается:
2. Прописываем в FF в about:config security.use_mozillapkix_verification=true
https://blog.dob.sk/2014/07/23/firefox-31-self-signed-certificate-sec_error_ca_cert_invalid/
forums.mozillazine.org/viewtopic.php?f=38&t=2884241
Самый лучший комменатрий:
Also shows up as unresolved for version 33 on https://www.mozilla.org/en-US/firefox/releases/ I am an administrator that deals with a wide variety of devices that have self-signed certificates that are only accessible from a LAN, and encounter this error daily. MOZILLA HAS DECIDED THAT IT KNOWS BETTER THAN ME WHETHER OR NOT TO ACCEPT A SECURITY CERTIFICATE WHICH ONLY EXISTS ON MY NETWORK! Now instead of having a sloppy work-around (v31,32) - it just no longer works (v33). After fighting with it a few hours today I have decided it is much easier to use Chrome (which lets me decide if a certificate is safe) as my default browser as this issue has plagued me thru 3 versions now (31,32,33) and is still not resolved.
