That means you're on 4.1.8 (latest firmware)
You say in another thread you removed PHP5. Had you tried to access Frontview after removing PHP5 but before the power cut?
How much data do you have on the device? It could be best to backup all your data, then do a factory reset and reload data from backup and manually re-configure, install add-ons etc. A factory reset on 4.1.7 or later (e.g. 4.1.8 your NAS is running) will give you 4k sector alignment which will be useful when you move to using 2TB disks.
If you don't want to do that you might want to open a tech support case (http://www.readynas.com/support
) and see if they can help.