My Kindle KT2 2014 upgraded to 5.12.2.2 while I left it charging a month ago. (not sure if it turned off airplane mode itself)
I'm trying to restore KUAL on it. The jailbreak hotfix package installs fine via "Update your Kindle", however the KUAL Booklet would be rejected with "An invalid update file has been loaded on your device" once unplugged.
Installing it via ";log mrpi" doesn't help. The screen turns blank after some "destroying package" and "Done, restarting UI", which should be what the OP is experiencing. Contents of "mrinstaller.log" follows:
Code:
[2022-03-16 @ 10:40:29 +0000] :: [MRPI r18896] - Beginning the processing of package 'Update_KUALBooklet_hotfix_44a61b6_install.bin' (KUALBooklet hotfix 44a61b6 I) . . .
Package 'Update_KUALBooklet_hotfix_44a61b6_install.bin' (KUALBooklet hotfix 44a61b6 I) is not targeting your FW version [!(3556150002 < 3791510038 < 3783100002)] skipping . . . :(