Automatic backup fails

Hi

I've setup two virtualmin servers with automatic backups - one to an FTP server and the other to S3. Both fail to run on schedule (daily in this case). However if I click on the back up and do "Backup Now" or "Backup in the Background", it works fine.

I included a screenshot of the setup.

Here's the error I get

Backing up mail and FTP user Cron jobs ..
    .. none to backup
 
    Copying Apache virtual host configuration ..
    .. done
 
    Copying Apache log files ..
 
Failed to write to /home/businDIR/.backup/businesDOMAIN.co_web_alog : Broken pipe at ../web-lib-funcs.pl line 1397, <SOURCEFILE> line 3864784.