Is this all being done in the web UI? At least in 2.0.3.9, it’s putting up a big fight when I try to add a password:
Unless this was a recent change, I’d be surprised if the web UI casually allowed one to remove the password.
Changing the archive password is also supposedly prevented although some people would prefer otherwise.
Ordinarily the Duplicati databases remember the password for you. This makes unattended backup possible.
Backing up the configuration preserves this (and other) information to make any loss-of-disk recovery easier.
That leads up to the next question, which is was the pc cleanup a minor one, or is its source data now gone?
This sounded like a new backup (maybe not of historical worth?). Is there something in it you need restored?