The Chinese jailbreak developer widely known as the Pangu team recently announced the re-release of pangu 8.0-8.1 Untether update 0.3.
"This is the untethered exploit installed by the Pangu 8.0-8.1 jailbreak tool. If you jailbroke your device with Pangu 8.0-8.1, this untether has already been automatically installed for you," reads the release note at the Cydia site.
The Pangu team previously released the Untether package version 0.3, which was later on pulled down by Cydia developer Jay Freeman commonly known as saurik, for booting issues. The Pangu team tweeted saying the reboot issue after the installation of v0.3 is due to the backup restore. Check out the description for Untether update 0.3 package in Cydia.
"For context, this is the update that we released about 10 hours ago and pulled because of reports of booting problems on a few devices. If you follow these instructions, it should be safe to update this untether on all iOS 8 devices," is what saurik, who confirmed the release of Untether update 0.3 on Reddit, said.
Adding on, the saurik's Reddit note says:
"Note: Before installing updates to this package (which will require a reboot), if, after the first time you ran Cydia on this device, you used the iTunes "restore from backup" feature (or otherwise used iTunes or iCloud to put old data back on your device), please reinstall Cydia Installer now (by going to that package and tapping Modify, Reinstall, and Confirm) to make sure your device can safely reboot with a passcode enabled."
Details about the contents of the untether update:
"Version 0.3 of this package fixes the issue where, on 32-bit devices (iPod 5, iPhone 4S/5, iPad 2/3/4, iPad Mini 1) a specific background process (launchd) would sometimes "spin", burning CPU and battery, or even heating up."
Reminder about other potential types of booting problems:
"Please also note that rebooting can surface other problems unrelated to the untether or Cydia. For example, having incompatible tweaks installed can cause problems upon rebooting.
You may have already installed this update earlier today. To check if you need this update, refresh Cydia and see if Cydia prompts you to install it."