Your app's connector could not connect to the database host, or it connected and failed authentication. TLS is a transport protocol, a newer version of handshaking or validating in more detail. TLS last I checked is at V1.3, and V1.0, V1.1 was discontinued, but that was years ago. If your database is hosted at home or in your shop, then that's a local connection, and could be a firewall blocking a port number for MySQL. If your using a cloud host, then perhaps they upgraded. But if you wrote the app personally, you should remember how that part works, and be able to fix it fairly quickly. EF has nothing to do with the connection to the database server. You can use Fiddler to watch the connection, or check error logs, there is something out there that will guide you. If it ain't broke don't fix it Discover my world at jkirkerx.com