"walk_down_proc+2D4" error on ReadyNAS 524

A ReadyNAS 524 that I set up for a friend in June has just crashed with the error message "walk_down_proc+2D4".  The unit was working fine til August 28 and then was shutdown properly because of the potential for flooding in Houston - was moved up in house and left til flood risk receded.  On September 10th was powered up again and Firmware 6.8.0 was installed.  After that, the machine developed issues.  On bootup, the error message appears and then it disappears. After booting, the web interface is accessible, and the mapped drives are accessible.  Mapped drives appear to be accessible and files can be read.  However, with any effort to save files to the 524 or to make changes in the web interface, the box crashes and is inaccessible - can not be shutdown either from the interface or with the power button - is locked in limbo and the only thing to do is pull the power cord.

These symptoms are almost identical to what my own 524 went thru a couple of months back and which I described in this thread, but the actual error message is different: 

https://community.netgear.com/t5/Using-your-ReadyNAS/Readynas-524-Crashing-quot-Walk-Up-Proc-359-quot-Error-Message/m-p/1340099#M134684

I'm assuming the box is going to have to be reset via a factory default restore and reset up all over again and all the files recovered and then copied back to the restored box?  Can someone advise me what this error message actually means (the message I had was a kernel error but I don't know about this one).

My frustration with the new ReadyNAS boxes can not be overstated ! Two brand new 524's cratering within 6 months of being installed.  I never issues like this in the 10 years I was running an NVX, NV+, and a Pro.