New Jetson Nano not booting - instead showing "recovery" screen

I had no problems booting my nano with the original image on a 16GB sd card, but got the screen shown at the top went I tried the jetbot 63GB image on a 64GB SanDisk Ultra Plus. I tried a different computer with a different operating system (Linux and Mac) with the same result. I have not been able to discern from the forum a definitive next step.