Cancelling a large upload not working

Cancelling a large upload does not really work. Try to upload a file that takes longer than 20 seconds, and try to cancel it. Tested on many servers, the progress window goes unresponsive and I have to terminate the process.

Using WinSCP 5.5.6 4746 portable (zip) on Windows 8.1 Enterprise.

Thanks for your report.
What protocol?

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

I'm thinking the OP might be just a casual user of WInscp, like myself, I'm not really interested in making a log,and posting it, and finding out what protocols i'm using. To me the most helpful answer would be either "Yes it's a bug", or "Nope it works on my computer". Since an admin answered the question, that should be easy to make that determination. If I know it's a bug I have no further worries. If it is my computer I can choose to work around the bug, or spend a long time trying to pinpoint the problem. For the occasional time I might have to cancel a big file update, ctrl-alt-delete is a lot faster than logging everything and posting.

Anyway for me, cancelling a big file upload does hang the program. Win 7, ftp with explicit encryption, I post this bc it helps other users know that the problem exists, if they encounter it.

To cancel in-progress downloads you need to use SFTP. It does not work with SCP. Also SFTP is a lot faster.

Pathduck wrote:

To cancel in-progress downloads you need to use SFTP. It does not work with SCP. Also SFTP is a lot faster.

I am using FTP with explicit encryption. I was not using SCP. Do you also think cancel-in-progress does not work with FTP?

42 Mb file, tried canceling after about 1/4 the way done. Won't cancel, have to kill task.

tempuser wrote:

42 Mb file, tried canceling after about 1/4 the way done. Won't cancel, have to kill task.

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

It happens to me as well. FTP with no encryption. Latest WinSCP version.

This is a problem that STILL has not been fixed. I have downloaded the latest version (5.9.5) and it still refuses to cancel a file being uploaded. I have to terminate the winscp task. Very annoying. Back to filezilla.

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

This bug I found in January 2017 when I wanted to switch my ftp client for WinSCP, but this bug was really annoying.
Today I found this topic and I really hope that you will fix it if someone give you more information about it.

Now about bug:

When I'm trying to upload any file that needs for example 1-2 minutes for uploading (10-20 Mb) and if I want to cancel uploading, i press cancel button, WinSCP stop response and i can only terminate process to exit.

Using WinSCP 5.9.5 with “Explorer” interface on Windows 10. It happens for any FTP connection, but with SFTP it is ok.
Session log file is attached.

Alexey wrote:

This bug I found in January 2017 when I wanted to switch my ftp client for WinSCP, but this bug was really annoying.
Today I found this topic and I really hope that you will fix it if someone give you more information about it.

Thanks for your report.

Can you send me an email, so I can send you back a debug version of WinSCP to track the problem? Please include link back to this topic in your email. Also note in this topic that you have sent the email. Thanks.

Email was sent.

So this original post was made in 2014. It was followed up on in 2015 through 2017. It's now almost 2021, and this bug still exists. The original poster laid out the two simple steps needed to replicate - upload a large file and then cancel. It would have taken anyone less time to simply replicate than posting asking for logs and whatnot. I guess there's really not any interest in addressing the bug.

For what it's worth, this happens using the FTP protocol. SFTP allows the upload to be canceled, but not FTP. The program becomes unresponsive, and the upload transfer speed slows to a crawl. The upload continues, slowly, the window remains entirely unresponsive and can only stopped by killing WinSCP using the Windows task manager.

Thanks for your report.
I have sent you an email with a debug version of WinSCP to the address you have used to register on this forum.