What is it?
This TLS finding means the probe could not complete a TLS handshake with the target. Common causes include no TLS service on port 443, SNI mismatch, unsupported protocol versions, cipher negotiation failure, or an invalid certificate chain.
Why does it matter?
If browsers or API clients cannot complete TLS negotiation, the HTTPS service may be unavailable or untrusted. TLS handshake failures can also hide more specific certificate problems until the server configuration is corrected.
How to fix it?
Confirm HTTPS is enabled for the exact hostname and that the certificate chain is valid.
openssl s_client -connect example.com:443 -servername example.comConfigure SNI for the hostname, install the full intermediate chain, enable TLS 1.2 or TLS 1.3, and verify that the firewall or CDN is forwarding HTTPS traffic correctly.