Tray Icon does not start after setting a UI password (Service Mode)
Duplicati Tray Icon Silently Dies with --no-hosted-server arg #3137
describe some of the things that can go wrong. Your situation sounds like a permission problem, where TrayIcon running as your user is unable to read Duplicati-server.sqlite in the SYSTEM account profile in C:\Windows\System32\config\systemprofile\AppData\Local\Duplicati
Possibly you can change the ACL, but I’m not sure how well protected it is. SYSTEM is pretty secure…
Another option is to move all of the Duplicati databases to a more accessible and safe location, such as C:\ProgramData\Duplicati as discussed in Migrating from User to Service install on Windows, or edit the service using Windows’ tools to have --server-datafolder pointing to whatever you choose. A big reason favoring moving the databases is that Windows version upgrades will move the profile to Windows.old.