I am not sure whether something change. Finally after two server restarts problem is gone. Windows serber 2008 Enterprise R2 SP1. I don;t belive this issue was fixed in previous versions as i faced it in very newer winscp version.

Thanks for your report.
Did anything change on the machine when the problem appeared? Windows update for example? What version of Windows are you using?

notice that i did restart machine because i thought it will help but didn't.

Hi guys,
I have couple services which are running more than couple months. All of them are using his own winscp.exe file. Yesterday i noticed all of them were logging same error every time. Till now i cant resolve it and don't know what's going on. I am using .dll version 5.7.2. What can be a problem here? I just saw that this problem was resolved in version 5.2.5 (https://winscp.net/tracker/996) but for me its just occurd. Can you help me out to fix that?

WinSCP.SessionLocalException: WinSCP process terminated with exit code 3 and output "", without responding (response log file C:\Windows\TEMP\wscp16F8.0398F535.tmp was not created). This could indicate lack of write permissions to the log folder or problems starting WinSCP itself.
at WinSCP.Session.Open(SessionOptions sessionOptions)