You’re gonna die laughing, but the reverse just worked for me. Brilliant idea. Full start to finish steps, for anyone else with the problem:
- Go to Sign in to your Microsoft account and search the page for “Duplicati.”
- Click on each Duplicati entry from the above page
- In the page that loads afterwards, click Remove. Repeat this until all Duplicati entries on the Manage page are gone
- In the Duplicati web UI, under Backup Destination, select Microsoft OneDrive V2
- In path, enter the folder path of the backup in the format Folder/ChildFolder. There are no symbols, indicators, or characters necessary for the root directory.
- Click the AuthID link and sign into your Microsoft Account
- Grant Dupilcati permissions in the dialog that pops up. This should automatically populate the AuthID field
- Expand Advanced Options
- Expand Add advanced option drop down menu
- Under Microsoft OneDrive V2, select authid: the authorization code
- In the authid field that opens up above the Add advanced option menu, copy and enter the AuthID generated from the link. Ensure the same AuthID is in the AuthID field under the Backup destination heading.
- Click Test Connection. You’ll get an error message about “duplicate authid”, but ignore it. The test should be successful.
- Set up the rest of the backup as the documentation specifies
- Run the backup and check the live verbose log to ensure there isn’t any connection error.
- After that backup has completed successfully, go back to the Advanced Options setting and remove the authid entry.
- Test the connection again. It should pass with no errors.
- Click Next until you can save the config.
- Click Save to save the config.