Let's try this.
Copy
Update_jailbreak_hotfix_1.16.N_install.bin to E:\, then restart to try install the JB Hotfix. If it failed, then that means your device is no longer jailbroken, and you need to wait for a newer JB method.
Note:
If you want to "un-jailbreak", then do these:
1. Factory reset the device (Settings > Reset). This will destroy JB hotfix/bridge that will automatically inject the developer/3rd party certificate, but the device is still jailbroken.
2. Reinstall the same software update. This will restore the original certificate.
You must do BOTH with that order.