KOReader not working on Kindle Paperwhite 3 (Wifi)

I've got my Kindle Paperwhite 3 on Christmas, jailbroke it properly (Downgrade to 5.7.4, install jailbreak and hotfix, upgrade back to 5.8.7, installed KUAL and MR Installer), installed KOReader, but I wouldn't work. So I reset my kindle, redid the whole jailbreak, now when I click an epub or PDF, the screen goes white, then it either redirects me to home screen or the KUAL Launcher. Any help would be appreciate.