Network error: Software caused connection abort but only by UPLOAD via SFTP

Dear Martin,

After upgrade to version 5.19.5 I have a problem uploading files (download from the same server works fine).
WinSCP is scheduled (as scheduled tasks) to upload new files every 7 Min.
It works 10–20 times, but than there is a message in log

Network error: Software caused connection abort

and each new start tries to upload the same file with the same error as result. After reboot the upload of the same file works again. I've seen this behavior for small csv files (1KB) but also for xls files (40–100KB).

What I have tried so far (found here in forum):

• disable optimize connection buffer size
  
• using additional PUT options -nopermissions -nopreservetime -resumesupport=off
  

but without success.

I'd very appreciate your help.

My log is attached.

Kind regards
Kyryl

What version were you using before? Does it still work if you downgrade?

Dear Martin,

Last version was 5.7.4
Unfortunately the installation package is not more available.

Regards
Kyryl

You can download any past version of WinSCP from:
https://sourceforge.net/projects/winscp/files/WinSCP/