This is not support forum for psftp. However I would recommend you to check the server log file first.

I set up SERV-U server with SFTP on port 22 on Windows Server 2003. I wrote a VB6 app that copies files then calls a command file. In the command file, I call psftp.exe and pass userid and password and a .txt file with commands and the server address (127.0.0.1). I call this .exe from Task Scheduler in Windows Server 2003(same server as above). Every morning I come in and check the log file, I see it did not connect to the SERV-U SFTP Server. I click on the .exe and it runs fine, copies the files to the SFTP server as it should. If I click on the .exe a second time, it does not connect to SFTP server. I opened up a command prompt and typed what is in the command file and I get the error: "Fatal: Server unexpectedly closed network connection" Sometimes it works and sometimes it does not. Please help....