Help me fix this issue" Host is not communicating ..."

Greetings, I'm getting this error while I try to transfer some files.

" Host is not communicating for more than 15 seconds. Still waiting… Warning: Aborting this operation will close connection!"

Note: If the problem repeats, try turning off Optimize connection buffer size.
Warning: Aborting this operating will close connection!

SCP / sFTP
Or please tell me how to down-grade winscp
Please help! this is getting on my nerves.

Please attach a full session log file showing the problem (using the latest version of WinSCP).

Why do you want to downgrade WinSCP? Did the problem start after an upgrade?

What is the resolution to this?

As you can I see, I never got any response from @earnestinence.
I you want us to investigate your problem, please follow the my instructions above.

I have the very same issue (or at least a very similar one). I have to transfer a large amount of files to a server using a SFTP protocol. On the beginning I had the "Host not communicating" issue only once in a while, but it became more frequent and more frequent, until I cannot even login to the server anymore without immediately loosing the connection again and again and again. The log-file I attached contains a few tries to connect to the server.

(Note: I censored user name, port number and the website name in the log file to "User", "No" and "No.com", similar to the passwords that are automatically censored)

Also: I already tried to uninstall and reinstall WinSCP hoping I would come back to a state where it still worked most of the time. Hover, this did not help, but apparently it was never uninstalled 100% since all my setting were kept.

@ThisUsernameIsTaken: In the log I see that you always abort the connection immediately, once you get the timeout message. Did you try waiting a bit? Do you get the error with any folder or only with the /data_ucla? Can you enter that folder with any other SFTP client?

I'm face with this issue as well after upgrade version to 6.3.4

I'm using WinSCP over year and never found any issue from logging in, upload and download anything before.

A log was attached below.

Please help me investigate and find a solution to fix this issue too.

Thanks & regards

@absolut: What WinSCP version were you using earlier? If you downgrade, does it work? Post a log file.