Fascinating. Good to see it fixed :)

I'm surprised that helped, however, as WinSCP for me automatically edits that to something that works. I suppose there's some difference.

I was testing with a different server - can't remember what it was using now without looking at the logs (something on Linux). Might be how the server's handle it that causes WinSCP to change it. Not like I'm looking at source code here so. Is is fascinating.

IT'S FIXED!!!!!!

Checked the users remote directory path and sure enough somehow /.. had been inserted before the /Foldername.
Removed the /.. and it worked fine.
No idea why the heck it was there but as per your responses it would appear FileZilla needs updating (which is in process as we speak)
HUGE thanks to all of you for your help with this one.

One last thing from me. With SFTP, I can get /../ to happen in the log (Remote directory: /../foo/ or /foo/../foo/) by manually editing the remote dir advanced setting and switching it in. WinSCP then complains about that, adjusts, and everything continues to work. After this, files still transfer fine and the file path is listed fine in WinSCP.

If it was WinSCP, I don't see how.

Thanks all, i've been through your posts, found the article that mentions a) the age of the client we're using and b) that specific issue where it inserts /../ into the filepath
I'm going to raise a change ticket now to update the FileZilla client on our servers and hopefully this will fix the issue.
It'll take about 2 weeks though but I'll post again here with the result.
Thanks all and speak soon.

Nevermind that one was FTP lol. But, still the version is over 2 years old.

Should also add

So, the user here is using a version without the fixed ./ bug. The user should fully update the server if possible. The ./ bug is fixed in 1.8.1 (2024-01-26).

There's be more path fixes since 1.5.3 (2022-08-11).

There was definitely this:

FTP Server: NLST would report a file names with a leading ./ path in certain cases, which confused some clients. Fixed.

https://filezillapro.com/filezilla-pro-enterprise-server-version-history/

I don't know what WinSCP code would think about a ./ and if it would somehow translate that as ../.

But, it's difficult to know and complicated. The server has a lot of power here to cause problems.

My guess is that it's likely a combination of some bug on the server that leads to the /../ path and WinSCP getting confused by the leading /...

Isn't FileZilla server including ..