(Windows)Version error when executing Backup or Restore Files

Hello, I need assistance with the following error. Could you tell me if there is a way to repair it without losing the backups?

Duplicati - 2.0.4.5_beta_2018-11-28
could not connect: the database has version 10 but the larges supported version is 8. this is likely caused by upgrading to a newer version and the downgrading. if this case, there is likely a backup file of the previous database version in the folder C:\users..\appdata\local\duplicati

the failure started after stopping the duplicati service and starting it again. It was not running backup when stopping the service.

Welcome to the forum @Cristian_Reds

Is that what you prefer to be on? How did you find that value? Version 10 could be 2.0.5.1 (less ancient).

Services complicate the picture. One can connect to the wrong Duplicati by accident if non-service is up.
In the GUI, see About → System info to look at UserName, BaseVersionName, and ServerVersionName.
Typically people adding a Windows service run as SYSTEM. The other two are the Program Files install (done by install from a .msi file) and any autoupdates that may have been done. Yours might be missing.

You can try different ports in the URL (such as 8200, 8300, 8400) to look for other Duplicati, or look in the Task Manager information. Seeing both Duplicati.Server.exe and Duplicati.GUI.TrayIcon.exe is a suspect unless you set up TrayIcon to run with –no-hosted-server which makes it just be an icon to control things.

You can also look around to see what 2.0.5.1 updates are somewhere, e.g. C:\ProgramData\Duplicati\updates for server, or C:\Users\<Duplicati user account>\AppData\Local\Duplicati\updates\ when running as you. Your message looks more like you’re not talking to the service, so maybe service is running 2.0.5.1 and your TrayIcon is running 2.0.4.5, but somehow is using the same database as server.

Most likely getting it back to 2.0.5.1_beta_2020-01-18 will do it, but why not run 2.0.6.3_beta_2021-06-17?