For whatever reason, the transfer fails.
Somewhere in that pile of files there is an incomplete file and I don't know which one.
Restarting the download, on the first file collision my choices are
- Overwrite all [damaged file is overwritten but massive waste of time and bandwidth]
- Overwrite if newer [damaged file is same date and does not get overwritten]
- Don't over write [damaged file remains in new archive]
But that is quite difficult and I would be very happy with "Overwrite all smaller files"