Error map
tlsv1 alert protocol version OpenSSL: error:14094410 / SSL alert number 70 — tlsv1 alert protocol version
SSL / TLS · layer 2, Network
Centre: this error. First ring: errors it is linked with (9). Outer ring: what those are linked with. Colours show the layer of a request each error belongs to. Click any dot to re-centre the map on it; hover to follow its connections. The centre dot opens the error page.
Directly related (9)
Chrome: Connection not secure — ERR_SSL_OBSOLETE_VERSION (old TLS 1.0/1.1)
The server only supports an outdated TLS version that current browsers no longer allow.
Chrome: This site can’t provide a secure connection — uses an unsupported protocol. ERR_SSL_VERSION_OR_CIPHER_MISMATCH
The browser and the server could not agree on a TLS version or cipher — the server is too old or misconfigured, or the browser is.
OpenSSL: error:num=20:unable to get local issuer certificate / SSL: CERTIFICATE_VERIFY_FAILED
The client could not build a chain from the server's certificate to a CA it trusts — the issuer is missing locally or the server…
Java: javax.net.ssl.SSLHandshakeException: Received fatal alert: handshake_failure
The server rejected the Java client's TLS offer — no shared protocol/cipher, SNI issue or a required client certificate.
OpenSSL: error:0A00018E:SSL routines::ca md too weak / error:140AB18F:SSL routines:SSL_CTX_use_certificate:ee key too small
OpenSSL's security level rejected a certificate signed with a weak hash (MD5/SHA-1) or with a small key (RSA < 2048).
OpenSSL: error:14094410:SSL routines:ssl3_read_bytes:sslv3 alert handshake failure (SSL alert number 40)
The server aborted the handshake with alert 40 — no acceptable parameters (cipher, signature algorithm, client certificate or SNI…
Firefox: Secure Connection Failed — SSL received a record that exceeded the maximum permissible length. Error code: SSL_ERROR_RX_RECORD_TOO_LONG
Firefox sent a TLS handshake but received plain HTTP back — you used `https://` on a port that serves HTTP.
OpenSSL: verify error:num=10:certificate has expired — notAfter=Jan 1 00:00:00 2025 GMT
OpenSSL's verification found a certificate in the chain whose validity period has ended.
OpenSSL: error:1408F10B:SSL routines:ssl3_get_record:wrong version number
The peer did not answer with a TLS record — you spoke TLS to a plain HTTP/SMTP port (or the reverse), or a proxy intervened.
Two steps away (26)
Cloudflare Error 525: SSL Handshake Failed
Cloudflare couldn’t complete a TLS handshake with your origin (SSL mode Full / Full strict).
ERR_SSL_PROTOCOL_ERROR (This site can't provide a secure connection)
The browser couldn’t negotiate TLS — the server sent an invalid response, often plain HTTP on the HTTPS port.
SSL error: tlsv1 alert protocol version / unsupported protocol / no protocols available
The client and server couldn’t agree on a TLS version or cipher, so the HTTPS handshake failed before any HTTP was exchanged.
Cloudflare Error 526: Invalid SSL Certificate
With SSL mode Full (strict), the origin’s certificate is expired, self-signed, or doesn’t match the hostname.
Let’s Encrypt / Certbot: Challenge failed for domain example.com — Invalid response from http://example.com/.well-known/acme-challenge/x: 404
Let’s Encrypt couldn’t verify you control the domain — the HTTP-01 challenge file wasn’t served, or DNS points elsewhere.
NET::ERR_CERT_COMMON_NAME_INVALID: Your connection is not private (certificate is for a different domain)
The certificate presented doesn’t include the hostname you visited — e.g. visiting www.example.com with a certificate only for ex…
Error: error:0308010C:digital envelope routines::unsupported
An old build tool (webpack 4, old react-scripts) uses a hash algorithm that OpenSSL 3 in Node 17+ disables.
OpenSSL: unable to load certificate / PEM routines:get_name:no start line (key values mismatch)
OpenSSL (or Nginx/Apache) couldn’t read the certificate or key — wrong file format, wrong file, or the key doesn’t match the cert…
Dart: HandshakeException: Handshake error in client (OS Error: CERTIFICATE_VERIFY_FAILED: unable to get local issuer certificate)
The app refused the server's TLS certificate because it is self-signed, expired, missing intermediates, or the device clock/CA st…
javax.net.ssl.SSLHandshakeException: PKIX path building failed: unable to find valid certification path to requested target
Java doesn’t trust the server’s certificate chain (self-signed, corporate proxy CA, or missing intermediate).
OpenSSL: SSL alert number 112 — tlsv1 unrecognized name
The server did not recognise the hostname sent in SNI and rejected the handshake (or an alert/warning is logged).
Java: javax.net.ssl.SSLHandshakeException: No subject alternative names matching IP address 10.0.0.5 found
Java checks the hostname against the certificate's SANs and found no matching entry (for DNS names or IPs).
OpenSSL/Nginx/Apache: error:0909006C:PEM routines:get_name:no start line / unable to load Private Key
The server or tool cannot read the private key file — wrong format, encrypted with a passphrase, wrong path, or a certificate pas…
Nginx: [emerg] SSL_CTX_use_PrivateKey_file("/etc/ssl/server.key") failed (SSL: error:0B080074:x509 certificate routines:X509_check_private_key:key values mismatch)
The private key does not belong to the certificate configured in the server.
OpenSSL: Error outputting keys and certificates — Mac verify error: invalid password?
A `.p12`/`.pfx` file could not be opened because the password is wrong, or its encryption is unsupported by your OpenSSL version.
cURL error 35: OpenSSL SSL_connect: SSL_ERROR_SYSCALL in connection to host:443
The TLS handshake failed — protocol/cipher mismatch, a proxy interfering, or the server closed the connection.
Firefox: Secure Connection Failed — SSL_ERROR_NO_CYPHER_OVERLAP (no common cipher)
Firefox and the server share no TLS cipher suite, so the secure handshake cannot even start.
Python: ssl.SSLEOFError: EOF occurred in violation of protocol (_ssl.c:2396)
The server closed the TLS connection abruptly without a proper shutdown, usually because it rejected the handshake or dropped the…
Firefox: Peer's Certificate has expired. Error code: SEC_ERROR_EXPIRED_CERTIFICATE
Firefox found an expired certificate in the chain presented by the server.
Firefox: Websites prove their identity via certificates — the certificate is only valid for other names. Error code: SSL_ERROR_BAD_CERT_DOMAIN
The certificate does not include the hostname you typed.
Nginx: [emerg] no "ssl_certificate" is defined for the "listen ... ssl" directive in /etc/nginx/sites-enabled/default:3
A server block listens with `ssl` but has no `ssl_certificate` and `ssl_certificate_key`.
NET::ERR_CERT_DATE_INVALID (certificate expired)
The site’s certificate has expired (or isn’t valid yet) — or the device clock is wrong.
Certbot: Failed to renew certificate example.com with error — The following certs could not be renewed: /etc/letsencrypt/live/example.com/fullchain.pem (failure)
`certbot renew` failed for one or more certificates, so they will expire if you don't fix it.
SMTP: [SSL: WRONG_VERSION_NUMBER] wrong version number — SMTP over SSL on a STARTTLS port
Your client tried to start TLS immediately on a port where the server speaks plain SMTP first (or the reverse), so the handshake…
Python requests: HTTPSConnectionPool(host='api.example.com', port=443): Max retries exceeded with url: /v1 (Caused by SSLError(SSLCertVerificationError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] ...')))
The `requests` call failed during the TLS step and exhausted its retries; the real reason is in the nested SSLError text.
gRPC: rpc error: code = Unavailable desc = connection error: desc = "transport: authentication handshake failed: x509: certificate signed by unknown authority"
A gRPC client could not complete TLS to the server — untrusted certificate, name mismatch, or plaintext/TLS mismatch.
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