Sadly (or maybe gladly if one is security-worried), it runs as you, and even if you were an Administrator there’s no special power until you endure the UAC prompt that Windows will likely want before granting.
I don’t know exactly what you saw, or when. Sometimes About → Show log → Live → Warnings helps.
Maybe test that before converting to the service, if this issue occurs often (and it sounds like it does…).
You can also see if anything is in the job logs, as an error or warning typically has a one-liner put there.
There’s at least one way for the database to interfere with itself. IIRC it involves auto-cleanup such as
Large job stopped halfway. Stuck in loops, either “database is locked” or “No filelists found on the remote destination” EDIT: auto-cleanup bug?
If you don’t set the option, then this wouldn’t be your situation, but the live log check seems worthwhile because it would be best to know what’s going on. If you see a message arrive, clicking may get more.
EDIT:
Google search is seeing some formats of this message where a file is seen after “file”, but not for you?
This makes determining problem more important. If it happens mid-backup, it’s probably on source file.
Database problem would likely be during startup, but maybe only if auto-cleanup option was chosen.