Backing up Windows server 2008R2, UR server reports 'No paths to backup configured', client log says 'can't access path to backup'

Perhaps deselect MSSQL component backup, either manually via “configure components to backup” https://www.urbackup.org/backup_mssql.html or set “Windows components backup configuration” in the advanced settings to default=0 instead of default=1 on the server.