TLS 1.2 issues SQL 2022. What do these error messages mean.

Question

I have SQL Server 2022 Developer edition running with enforced encryption (TLS 1.2). For some reason I have frequent disconnects, from the logs it states that TLS is successfully activated and also the certificates are loaded.

More often I get the first error.. when I forcefully try to connect with -tls1_2 I get the second.

2025-03-03 05:16:30.47 Server      Error: 4014, Severity: 20, State: 10.
2025-03-03 05:16:30.47 Server      A fatal error occurred while reading the input stream from the network. The session will be terminated (input error: -2146893052, output error: 0).

2025-03-04 05:43:06.47 Logon       Error: 17821, Severity: 20, State: 1.
2025-03-04 05:43:06.47 Logon       A valid TLS certificate is not configured to accept strict (TDS 8.0 and above) connections. The connection has been closed.

I've gone through all documentation and AI bots.. but I cannot find out what is causing these disconnects.

Answer 1

The first error suggests that there are network issues or the client is sending malformed TDS.

The second error means what it says. That is, you need to actually configure a certificate for Strict to work. And note that Strict implies TLS 1.3, not TLS 1.2.