blank file after upload

I am using WINSCP.COM version 5.7.7 build 6257 to transfer files to an sftp site using a private key. The upload runs via a batch script called for each file it uploads (normally 3 files) which is basically as shown below where parameters are substituted.

echo open sftp://%4:%5@%3 -privatekey=%6 >grgtransfer.sftp
echo cd %7 >>grgtransfer.sftp
echo put %1\%2 >>grgtransfer.sftp
echo close >>grgtransfer.sftp
echo exit >>grgtransfer.sftp
winscp.com /log=%logfile1% /script=grgtransfer.sftp

The script logs on and uploads OK except the first file it uploads always appears blank after completion, even though a listing of the file shows a valid byte size.

I have attached a log file showing the upload (blanked secure data items) for all 3 files showing the first file as successful and valid byte size. I am not a comms expert but can anyone see what might be the cause from the log detail.

Is it really only the first file? Did you check the third too?

Did you try to test your script against another server? (not Globalscape)

I know it sounds unbelievable but it is only the first file that does not upload successfully. I have even tried uploading in multi file mode using 'mput %1\*.txt' command but that has the same issue.

As to using WINSCP on another server, I have but only to upload a single file and that seems to work OK.

I thought the log file would shed some light as to what the server might be doing which you could interpret. Do you have any other recommendations ?

Sorry, no. The log file is identical for the first and the third file. I expect this to be a server-side problem.