A connection was successfully established with the server, but then an error occurred during the pre-login handshake

Question

I am getting following error when i am trying to connect Production DB from Local Environment.

I was able to connect Production DB before, but suddenly i am getting f

Answer 1

In my case, it was a TLS protocol mismatch between a Raspberry Pi hosting a .Net Core 3.1 app requesting to a Windows Server 2012 with MSSQL. I tried many changes of TLS protocol version on the Windows Server side without any effect. I finally found this post https://github.com/dotnet/SqlClient/issues/126, indicating modify the client side, ie to update the /etc/ssl/openssl.cnf on the RPi side, and that worked great for me.

Answer 2

• Save your work,
  
• Close Visual Studio, then
  
• Re-open your project

This worked for me.

Answer 3

I was getting the exact same problem with no chnges to the code base or servers. It turned out to be that the DB server was running at 100% CPU and SQL Server was being starved of any CPU time, which caused the timeout.

Answer 4

Running the following command worked for me:

netsh Winsock reset

Seen at https://serverfault.com/a/487139/250527

Answer 5

I had this same problem and was having no luck with the suggested fixes. I then came across this article and saw the comment from Mirrh regarding a program called Sendori blocking the LSP. No idea how it got on my computer but there it was and removing it fixed the issue.

If the article doesn't work just check your Programs and uninstall Sendori if you see it.

Answer 6

I experienced this error and did all the suggestions from you guys here but none had any effect for my error.

I caught the culprit: if you are using *.ini file for your system, you might want to check what server name was input there and make sure it is the same as the one in your web.config connection string.