I'm using Cyberduck on a Windows machine and drag & drop works from Cyberduck works fine for local folders on the computer.

However, if the drop target is a network folder in Windows Explorer it fails. When I drop a file or folder, a 0 byte file (no extension) is created in the target with a seemingly random file name (for example: 894955e9-a2a9-46f9-ba8b-74410602b538) but the actual file is not downloaded. The download progress window doesn't pop-up either.

For full reference, Cyberduck 5.1.0 is installed on a Windows 10 VM which runs on a Linux Host via Virtualbox. The network folder is a virtualbox shared folder which is mounted as drive E. All other applications read and write from this location just fine. Finally, Cyberduck is connected to an HTTPS WebDAV server.

I have tried this from a Win7 VM and had the same issue.