Trying and failing to jailbreak my Kindle paperwhite gen 5 (serial number starting with B024, firmware 5.6.1.1) and get Kual and Koreader up and running. Following these instructions and trying it twice, doing a factory reset after the first time failed and trying again, but just get an error reading “This item is not signed by an authorised developer. Please contact the developer.” when trying to launch Kual after I’m done.

Posted on the forums looking for help
https://www.mobileread.com/forums/showthread.php?p=4578869#post4578869