martin wrote:

You have some strange character (3D E2 80) in front of the fingerprint (where ? is):
-certificate=?08:25:47:29:84:06:c3:2b:64:43:09:34:9b:bc:76:d3:ad:75:36:7f

Thank you Martin for your Tip! After some research I found that security software Safetica blocked communication with my FTPS server. When we made exception for our server, everything works like a charm.
Thank you.

You have some strange character (3D E2 80) in front of the fingerprint (where ? is):
-certificate=?08:25:47:29:84:06:c3:2b:64:43:09:34:9b:bc:76:d3:ad:75:36:7f

Hello Martin,
I have strange problem with WinSCP batch running from Powershell script.
Script is connecting to IIS FTPS server with Let's Encrypt certificate.
In my script I'm using -certificate= statement to tell WinSCP to trust server certificate.
I seen "Unable to get Local issuer certificate" in WinSCP log. I don't know what is wrong, because this "issuer" is not real issuer but client from which I ran the script... And this "issuer" certificate is computer self-signed certificate.
I don't understand why WinSCP verifies certificate of client itself (when it is not required at server side).

This computer is joined in windows domain environment. I'm able to connect through WinSCP GUI on this computer or by same batch script from non domain computer.

Log is attached (real domain name is replaced by "domain" string).