I hope is ok to post in this thread, since I'm having the same problem.
I have a kindle PW4, sw version 5.17.1 that I have jailbroken a few months ago. I installed KOReader on it following the instructions of kindlemodding.org. Loved it!
I was removing some custom fonts from the Koreader fonts folder when it stopped working. Now it won’t start Koreader, when I select the Kual booklet -> Koreader ->Start Koreader, instead of showing the “starting Koreader ...” message at the bottom of the screen, it briefly shows a blank before returning to the Amazon library screen.
I have tried mergen3107 suggestion (Turn off wi-fi, restart (simple restarts) your Kindle twice, then run Hotfix “book”) the hotfix is successful but the behaviour is the same.
I’m desperate to have Koreader working again, anyone able to help?
