Good news! Try installing the Jailbreak Hotfix:
- Download JailBreak-1.16.N-FW-5.x-hotfix.zip from snapshots.
- Extract the hotfix to the usb root
- Install with Update Your Kindle.
If that doesn't work:
- Download kindle-jailbreak-1.16.N-r16683.tar.xz from the snapshots thread
- Place Update_jailbreak_bridge_1.16.N_install.bin in MRPackages
- Launch KUAL > Helper > Install MR Packages