Error code

Firefox SEC_ERROR_CERT_SIGNATURE_ALGORITHM_DISABLED

FIREFOXSEC_ERROR_CERT_SIGNATURE_ALGORITHM_DISABLED
Browser Error Code· An error code shown in a web browser when a page fails to load.

What it means

The certificate uses a signature algorithm that Firefox has disabled for security reasons.

How to fix it

  1. Contact the site owner to reissue the certificate using SHA-256 or stronger.
  2. Update your Firefox version if this appears on a modern certificate.

Not affiliated with Firefox. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.