I just ran into this error myself. Win10, Duplicati as a service, 2.0.4.5_beta_2018-11-28.
Remote is to a mapped network drive on my Asus router
Backups have been running fine for a while, otherwise (as far as I know - basically, I didn’t see errors).
The last backup was on Friday last week, and this just started happening after I returned from a business trip, so there was no tinkering involved along the way. I tried repair, and it didn’t find anything wrong. I’m currently in the middle of a “recreate database” which is taking a very long time (been running for about 12 hours now, which seems like a lot for such little data (relatively… I only have a 75GB backup).
In full disclosure, I did stop the backup on Saturday as it was backing up some large and unnecessary files. I stopped the backup in the interface, and told it to stop immediately (instead of waiting for the file to complete). I then deleted those files and restarted the backup. I thought it ran without issue, but maybe it didn’t and that’s what caused it?
I also wish I had seen gabor’s recommendation before so I could have tried that instead, but I’m in it now, so I’ll let it go until it finishes, I guess.
It surprises me that it would take this long to rebuild the DB. Again, I’m running local, so if I ran over the GBE wire, I should see 1Gbitps rates for a normal backup. 75GB = 600Gbit, so theoretically I’d get this backup done in 600 seconds, or 10 minutes. Theoretical speeds aside, even if I only got 10% of throughput, I’d expect to see 100 minutes, or less than 2 hours. Why does it take so long to rebuild since that’s not actually performing a backup? (I don’t see that much activity on the drive during this process… so it’s not network limited?) Or maybe my math is way off?
Still, I’d like to know what the official fix is… or what the workaround fixes are in case this happens again.