How to fix SSPI handshake failed with error code 0x8009030C?

The error code 0x8009030c indicates that the Security Support Provider Interface (SSPI) handshake failed. This can happen for a number of reasons, including an incorrect password, a problem with the security credentials, or a problem with the network.

• Check the system event log for any errors that may have occurred around the time that the handshake failed
• Try to connect to the SQL Server using a different client application, such as SQL Server Management Studio
• If the SQL Server instance is configured to use SSL, make sure that the client application is configured to trust the SQL Server's SSL certificate

1. Check the system event log for any errors that may have occurred around the time that the handshake failed

1.Open the system event log. 2.Look for any errors that may have occurred around the time that the handshake failed. 3.Fix any errors that were found.

2. Try to connect to the SQL Server using a different client application, such as SQL Server Management Studio

1. Open the SQL Server Management Studio.
2. Connect to the SQL Server instance.
3. Right-click on the server name and select "Connect to Server".
4. Enter the server name and the port number.
5. Click on the "Connect" button.
6. In the "Server Message Block" window, click on the "Error Reporting" tab.
7. In the "Error Reporting" window, click on the "Events" tab.
8. In the "Events" window, click on the "Logins" tab.
9. In the "Logins" window, click on the "Login" event.
10. In the "Login" event, select the user name and the session ID.
11. Click on the "Execute" button.
12. In the "Command Prompt" window, enter the following commands: sqlcmd -S "localhost" -U "UserName" -P "Password" sqlcmd -S "localhost" -U "UserName" -P "NewPassword"
13. If the command is successful, the output will be similar to the following: Instance is up and running. If the command is not successful, the output will be similar to the following: sqlcmd: error 0x8009030c

3. If the SQL Server instance is configured to use SSL, make sure that the client application is configured to trust the SQL Server's SSL certificate

1. On the client computer, open the "Windows Defender Security Center" and click on the "Protected Sites" tab.
2. Under "SSL Certificate Trust Policy", click on the "View Certificate" button.
3. Right-click on the certificate that is associated with the SQL Server instance and select "Properties".
4. On the "Details" tab, click on the "Trust" button.
5. Click on the "Configure" button and select the "Windows" radio button.
6. Select the "SSL" checkbox and click on the "OK" button.
7. Close the "Protected Sites" tab.

Some users might also have success with the following opitons:

1. Make sure that the SQL Server service is running and that the server is accessible from the network.
2. Check the application and system logs for any other errors that may be related to the problem.