So we have to block it to prevent destruction of crontab file.
13:30 Jun/10/2015: 1: "/home/tmp/lxtmp__var_spool_cron_admin09gLkZ":2: bad hourerrors in crontab file, can't install. [(__system__) 'crontab' '-u' 'admin' '/home/tmp/lxtmp__var_spool_cron_admin09gLkZ']
Try adding a cron with just "2" in command.