When Firefox web browser checks a security certificate, it also checks with the issuing authority if the certificate is valid. It appears that, near a certificate’s expiration date, the issuing authority may release a new certificate. The two certificates have conflicting expiration dates.
For reasons unknown, this caused Firefox to report a sec_error_revoked_certificate error and refuse to allow you to connect to the site!
To resolve this, presumably at the same time reducing the security of your browsing, complete the following:
For PC Users:
- Open Firefox.
- Go to Tools the top menu and select Options.
- Click the Advance tab.
- Click the following button:
Encryption, then
Certificates, then
Validation - Check “Do not use OCSP for certificate validation.”
- Click OK and restart Firefox.
For Mac Users:
- Open Firefox.
- Go to Firefox in the top menu and select Preferences.
- Click the Advance button.
- Click the following buttons:
Encryption, then
Validation - Un-check “Use the OCSP to confirm the validity of certificates.”
- Click OK and restart Firefox.