mount-block-root-25e boot error after power cut

I had this same problem and i was trying to reload software on multiple usb drives and nothing was working. Then while searching on the netgear community for a solution, someone mentioned to run the USB software as administrator. So, I plugged in my USB drive right clicked the usb exe file and clicked on run as administrator and reformatted drive. I reinstalled the recovery software and tried loading from usb and it worked. Im not sure if running as administrator made a difference but as soon as I did that, the nas was able to recover from usb. Hopefully this works for anyone with the same issues.