ERR_SSL_VERSION_OR_CIPHER_MISMATCH on Nginx
Why it happens on Nginx
An ssl_ciphers line copied from an old hardening guide can leave the server offering only ciphers Chrome removed, so the handshake ends with no shared suite.
The fix on Nginx
Replace the directive with the current Mozilla intermediate list and set ssl_protocols TLSv1.2 TLSv1.3, then reload. Avoid pinning a single cipher — it breaks on the next browser release.
Is ERR_SSL_VERSION_OR_CIPHER_MISMATCH happening on your domain?
The SSL check enumerates exactly which protocol versions and suites the server accepts, turning guesswork into a list.
Free, no signup. Runs from outside your network, which is the only way to tell a server fault from a local one.
If that didn't fix it
Nginx has its own failure mode, but ERR_SSL_VERSION_OR_CIPHER_MISMATCH has a wider set of causes that apply everywhere. The most common one overall is: the server only supports tls 1.0 or 1.1.
All causes and fixes for ERR_SSL_VERSION_OR_CIPHER_MISMATCH