Setup Server DB encryption with Windows Credential Manager

Arh, that one! I spent a lot of time figuring this out, but it is caused by (at least) fr-CA locale treating a value such as 0s to be a valid date. It has been fixed in canary builds.

You have 3 options:

  1. Don’t use fr-CA locale for date/time
  2. Manually edit the database
  3. Use a canary build

You can see the full discussion.

For step 2, you need a tool such as SQLiteBrowser, edit the file Duplicati-server.sqlite edit the table Option and change the value for startup-delay from the current 0s to a blank. Then save, and it works again.