ReadyNAS Pro 6 Pioneer Edition cannot boot after OS4 to OS6 upgrade

Greetings! 

I had upgraded my ReadyNAS Pro 6 Pioneer Edition to OS6, and when it first rebooted, all appeared well. The hard drives were building a new RAID set, and Raidar saw the device on the network, I had a backup of the data that had been on the ReadyNAS prior to the upgrade, and built that backup on a ReadyNAS314 (running OS6), so that I could attempt to move the RAIDset from the 314 to the upgraded Pro 6. When I put the drives in and booted, i saw a message about "No IP" and that the device was booting into safe mode. Since the device had no IP I could not troubleshoot across the network. I put the original disks back in, and got the same result. I tried the reset button and I tried booting with an OS 6 recovery USB. Finally the device would no longer boot, and only showed the ReadyNAS logo on the front.

I noticed this thread which seems to  be similar to my experience:   https://community.netgear.com/t5/Using-your-ReadyNAS-in-Business/ReadyNAS-Ultra-6-Stuck-on-quot-READYNAS-quot-prompt-with-or/m-p/1708051#M177906

I'm thinking that I lost the same data that the person in that thread had lost as well.

Can anyone help me getting this ReadyNAS back up and running with any OS version? It's a 12-year-old NAS, but had been functioning perfectly. I just wanted to move to larger drives.

Thanks in advance!

Robert