If this is a new product and it is the first time it is being setup i.e. disks are clean than please follow the quick setup guide (see manuals at download page).
If this situation is encountered after a successful setup, you need to run LSupdater.exe from a windows PC to recover the unit. Current, MAC version of Lsupdater application can not recover crashed units only Windows version can .
Alternatively, if end user does not care about the data, attache Hard disk to any PC via usb/sata adapter and clean all hard disk partitions. Next, re-initialize the unit as instructed in QSG setupguide.