ERR_SSL_VERSION_OR_CIPHER_MISMATCH is the message Chrome shows when it cannot agree on encryption terms with a website. The handshake ends before any page content is sent, so there is nothing to display and no option to continue anyway. You may also encounter variations of this error: That second line is not a paraphrase. It is the […]
A modulus mismatch means your SSL certificate and your private key are not a matching pair. The certificate was issued for one key, and the file your server is loading is a different key. Because a TLS server has to prove it holds the private key belonging to the certificate it presents, there is nothing […]
When Chrome blocks a page with NET::ERR_CERT_AUTHORITY_INVALID, it is saying something narrower than “the certificate is bad”. The certificate may be perfectly valid: issued by a real Certificate Authority, matching the domain, and still well inside its validity period. What failed is the chain. Chrome could not link that certificate back to a root certificate […]
NET::ERR_CERT_DATE_INVALID is one of the narrowest errors Chrome raises. It is not a verdict on who issued the certificate, on the domain it was issued for, or on the strength of the encryption. It says one thing only: at the moment of the connection, the browser’s clock fell outside the period the certificate is valid […]
Most browser certificate warnings mean something was configured wrong. NET::ERR_CERT_REVOKED is different. It means the certificate was issued correctly, was accepted as genuine, and then the Certificate Authority that issued it deliberately cancelled it before its expiry date. Nothing is broken in the sense of a typo in a config file. Somebody decided this certificate […]
NET::ERR_CERT_SYMANTEC_LEGACY is a Chrome certificate error from a very specific moment in web history. It marked a certificate that traced back to Symantec’s old certificate authority, the infrastructure behind the Symantec, Thawte, GeoTrust, RapidSSL, VeriSign and Equifax brands, which Google removed from Chrome’s trust in 2018. That story is finished, and so is the error […]
Chrome shows NET::ERR_CERT_WEAK_SIGNATURE_ALGORITHM when a site presents a certificate signed with a hashing algorithm the browser no longer accepts. In practice, that algorithm is SHA-1. The error reads like a server misconfiguration, but it is narrower than that. A signature algorithm is written into a certificate at the moment the Certificate Authority signs it, and […]
NET::ERR_SSL_PINNED_KEY_NOT_IN_CERT_CHAIN is one of the few Chrome errors that almost nobody sees for the reason the internet says they see it. Most guides describe it as a site owner’s configuration mistake, something you caused by pinning the wrong key and can undo by reinstalling your certificate. That has not been true for years. The error […]
Most certificate problems announce themselves. This one does not. When an intermediate certificate in your chain expires, your own certificate stays valid, your monitoring stays green, and the site keeps loading perfectly on the machine you check it from. Meanwhile some share of your visitors cannot reach you at all, and the ones who can […]
Most SSL connection errors give you something to try. This one does not. When Chrome shows NET::ERR_CERTIFICATE_TRANSPARENCY_REQUIRED, the connection was refused because of what the site’s certificate contains, or rather what it fails to contain, and none of the usual visitor-side fixes take part in that decision. This guide explains what the error actually checks, […]