Can't understand error message and what to do now

I am getting an error telling me to do something I don’t quite understand. I suspect it has arisen due to a failure of my NAS I use for backup. It caused my network drives to be inaccessible. I have now made the network drives accessible again but need a new NAS as an ancient drive has failed and they are no longer mirrored. I had to remove the failed drive to power up the NAS.

The error message is:
The backup storage destination is missing data files. You can either enable --rebuild-missing-dblock-files or run the purge command to remove these files. The following files are missing:,

How do I do either of these?

Initiating the backup again manually leads to a message that 21 files are missing and offers a Repair button. This does nothing other than bring up the same message as above.

This is not very user friendly - it needs to have an easy to understand method of recovering after such an error or it is unsuitable for non techie users. It looks as if I may have to abandon Duplicati when I get my new NAS if that has suitable backup software.

I am running Duplicati as a service and backups are scheduled. I am normally running as a standard user on Windows 10.

Duplicati is totally failing to run opened the next day presumably replaces this, but I think what it means is


on Options screen in Advanced options section, then run Repair, but it doesn’t appear to work well…

Quoting About → Changelog

  • Removed automatic attempts to rebuild dblock files as it is slow and rarely finds all the missing pieces (can be enabled with --rebuild-missing-dblock-files).

My guess about purge is it refers to The PURGE-BROKEN-FILES command as described in manual at
Recovering by purging files. Confusingly, there’s also a purge to let you purge files of your own choosing.