For what it's worth, I have a kindle DX that might have gotten into the "not a test kindle" anymore and unable to launch KUAL state after I tried to enable wireless with a non-standard SIM card swapped for the one provided.
I tried wireless off restarting, re-installing jailbreak (which I was pretty sure would do nothing and is not recommended but I did it based on "jailbreak contains dev certs"), then finally installing MKK (DevCerts). That last one did it. I can launch KUAL again.
saw some info at
https://www.mobileread.com/forums/sh...d.php?t=277256 but started this fresh one as suggested.