I'm still having this issue and done multiple reboots following installing DevCerts (K5 ALL) in root.
I installed jailbreak
kindle-jailbreak-1.16.N-r19426
DevCerts appear to install with Update kindle
But launching KUAL-KDK-2.0.azw2 tells me it's not signed.
I have run emergency.sh and now have the .done and other two files. However,
;log mrpi does not show me the
Hush, little baby... and the cert file remains in
mrpackages
Here's my 411 info, does any of that help?