Flexible SLL Not Working Suddenly

I have not modified my site or configuration in about a month, and suddenly, someone tells me that they are seeing the following error:

# This site can’t provide a secure connection

**my domain** uses an unsupported protocol.

ERR_SSL_VERSION_OR_CIPHER_MISMATCH

The issue seems to exist only for one of my domains. I tested by rehosting the site in another EC2 instance and the same issue persists. Is it possible there was an error on Cloudflare’s side in processing the cert for my domain?

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I do understand why Flexible SSL is not the best choice. If I have ever had a project that needed security, I’ve used the Full (Strict) setting.

But the problem is that even just now… Using all of Cloudflare’s documentation and Origin Certificates, I am facing the same issue.

developers.Cloudflare[dot]com/ssl/ssl-tls/cipher-suites/

This makes me think that something is wrong with the certificate for traffic between Cloudflare and the browser. As was the case with Flexible.

I can further prove this by using a perfectly fine configuration for another site I run and putting it as a subdomain of this problem domain (both using Flexible). One works and the other doesn’t.

I am stuck. And I haven’t changed anything in years of operating this site on Cloudflare. Why now is it suddenly not working?

What’s the minimum TLS version you’ve set for your domain? If it’s 1.3 then that will exclude a lot of older web browsers and cause this issue.

Alternatively, your visitor may be using an old or outdated web browser that doesn’t support the TLS version that your site uses.

For example, Internet Explorer. IE throws this exact error when connecting over TLS 1.3

If you do not need encryption, simply set it to Off. You do not necessarily need to use SSL.

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