How do I format an HP-48GX FRAM Card?

[JDW]

Back in Jan. 2017, I purchased an 128K FRAM card and installed Meta Kernel on it using Hoppi. The card and Meta Kernel worked flawlessly all that time until today. But today when I press ON, I see this:

Warning:
Invalid Card Data

I've tried a soft reset and also the paper clip reset under the upper right rubber foot, to no avail. Pulling out the card and reseating it did nothing good.

I want to reformat/erase the card to see if that will even work. If it doesn't, that would mean the card may be dead.

How do I ERASE or otherwise FORMAT my 128K FRAM card in slot 1?