What changed on 11/1/2023? - old DotNet application fails on all 200+ machines

Question

I have an old .net that has been running on Windows since win7 and before
until 11/1/23 it was running on over 200 win10 and win11 machines

Now when It tries to post to the server, it fail with a DotNet error

What changed on 11/01/2023?

Unhandled exception has occurred in your application. If you click Continue, the application will ignore this error and attempt to continue. If you click Quit, the application will close immediately.

Object reference not set to an instance of an object.

Answer 1

You don’t give an error message, but most likely a service pack disabled TLS 1.0, 1.1 and 1.2.

https://techcommunity.microsoft.com/t5/windows-it-pro-blog/tls-1-0-and-tls-1-1-soon-to-be-disabled-in-windows/ba-p/3887947

Answer 2

Hi @ben bowden ,

Windows 11 version 23H2 is released on October 31, 2023.

Windows 11, version 23H2 known issues and notifications

For immediate help with Windows update issues, use the Get Help app in Windows or go to support.microsoft.com.

Best Regards.

Jiachen Li

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Answer 3

did you get the answer?