Always Trust Certificate on Microsoft RDP for MAC

Issue

After updating my macOS to Sonoma 14.4.1 (23E224) I can no longer connect to Windows machines via "Microsoft Remote Desktop" version 10.9.6 (2188).

I click on the remote connection, and then "Continue" as usual....

... the connection change into connecting state, but it hangs ...

... and no connection will be established to the remote PC.

Solution

Open the connection, then click "Show certificate" and expand "Trust"

change options from "Use System Defaults" ...

... to "Always Trust".

Confirm the changes by entering the system password ... and click continue to establish the remote connection.

If it doesn't work right away. Close the "Microsoft Remote Desktop" application, reopen it and try connecting again. It should work without even showing the certificate.

That's it.