I dealt with, and figured out how to resolve a SFTP session log file outputting in Chinese. I wrote a PowerShell routine that calls WinSCP.com (the latest version as of 6/23/23). When first implementing it, the session log file was outputting in English. A few days later, after further building on the PowerShell logic, the session log started outputting in Chinese. My Windows language is set to English (USA). I couldn't find any references on how to fix the issue on the internet. I searched WinSCP forum and documentation, and couldn't find anything about it either.
In the PowerShell logic, I was outputting an empty session log, to create it. In the WinSCP commands, I was designating the log file, pointing it to the empty, already created log. If the log already exists, the output was in Chinese. If you let WinSCP create the log, it outputs in English. I repeatedly tested, and got the same results.
Rex