Downgraded Duplicati, now won't start

I was having difficulty with the latest canary build, where it would hang forever on the initial file scan. Reading through the forums it seems there is an issue with where database access could take a very long time, with the advice to downgrade. I followed the instructions here to downgrade.

In my case, the previous version is, so I deleted the folder at /usr/share/Duplicati/updates/, and changed the “current” file to indicate

Starting the service back up, Duplicati exits immediately. If I try systemctl status duplicati, it indicates:

A serious error occurred in Duplicati: System.Exception: Failed to create, open or upgrade the database.
Error message:
The database has version 5 but the largest supported version is 4.
This is likely caused by upgrading to a newer version and then downgrading.
If this is the case, there is likely a backup file of the previous database version in the folder /root/.config/Duplicati
at Duplicati.Server.Program.GetDatabaseConnection (System.Collections.Generic.Dictionary`2[TKey,TValue] commandline
at Duplicati.Server.Program.RealMain (System.String[] args) [0x001cc] in <66004e16a6074efdaebb0aaaf058863a>:0
duplicati.service: Main process exited, code=exited, status=100/n/a
Unit entered failed state.
Failed with result 'exit-code'.

Any idea how to proceed?

Unfortunately, you’ve fallen into the “Why you might NOT want to downgrade” database issue mentioned at that link.

If you want to manually downgrade the database I think there are some instructions somewhere in the forum (let me know if you can’t find them) but I suspect it will be easier to “manually update” to a newer version than but NOT so new as to be

You SHOULD be able to just install something newer (like, which uses database version 5) “over” your current installation. This will change your “base” install from what it currently is (you MIGHT be able to see it in BaseVersionName at main menu “About” -> “System info”.

The everything-but-the-most-recent downloads can be found here:

I don’t know how to do it in Linux, but on Windows you can:

  1. download the zip file version from the above Releases link
  2. unzip it into a subfolder your “updates” folder (for you that would likely be something like ~/.config/Duplicati/updates/ or /root/.config/Duplicati/updates and on Windows likely C:\ProgramData\Duplicati\updates)
  3. if necessary, rename the unziped subfolder to be JUST the version number of what you unziped (so if you downloaded you’d name the folder
  4. restart any running server (service / daemon) or tray-icons

This is essentially doing a manual version of the GUI based update.

I’ve added a block to the “how to downgrade” guide that explains this in a slightly more organized way.

Thanks, that should be enough information for me to do a manual upgrade to in linux. I had a feeling I might be in a situation where the downgrade wasn’t a good idea :slight_smile:

I tried this:

  • Download the version using wget
  • Extract with dpkg -x duplicati_2.0.3.5-1_all.deb
  • Copy what looked like the correct folder to /usr/share/Duplicati/updates/
  • Modify the file current to indicate
  • Restart the service

No luck. There must have been something wrong with the file set I copied into the update folder, but I couldn’t figure out what it was.

Installing the version over my existing version did the trick, with dpkg -i duplicati_2.0.3.5-1_all.deb. Up and running!

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