The live module check refused smb-users: a key naming a user is the operator's value and may have no default, and a setting without one would refuse to compose mounts on every node until set. The username now goes in the source's URL (smb://<user>@<host>/<share>), percent-decoded; a password there is refused unsaid, and a source without a user waits for sources (hq ADR 0283, issue 386).