iPhone Cydia Eraser crashes out before completion

[Koenfucius]

My wife's iPhone 4S (running iOS 8.1.2 and jailbroken) is seriously misbehaving (see https://forums.macrumors.com/thread...en-iphone-4s-ios-8-1-2.2036106/#post-24380914 for any details) and I am trying to restore it to a clean iOS (without upgrading to 9.3.5), using Cydia Eraser.

The first problem I encountered was the "eraser.cpp:1410" error, but I discovered that downgrading Eraser from 0.9.32 to 0.9.18 might fix that problem.

So it did, and I can now happily run Eraser... until it crashes out back to the home screen. It does so at various times in the process, from within a few seconds to more than three minutes, but most of the time it happens while it is scanning through all the directories (it gets about 2/3 of the way at most, it seems).

I don't know whether Eraser needs lots of storage, but the device has about 10GB free of its nominal 64GB, so that would not appear to be a problem. I have also made sure there are no other processes running by swiping them away from the app switcher.

<later>

Just now Eraser crashed again, and within a few seconds the device spontaneously rebooted. Given the somewhat erratic behaviour of the device it's hard to say whether this is something to do with running Eraser consecutively, or something that would've happened anyway.

What could be happening here, and how can I make Eraser complete its process?

Many thanks!

<UPDATE>

Well it got in the unstable state again so I switched it off, left it for a couple of hours, and then switched it on. After it rebooted twice, it seemed to be in the stable state again (no reboot for more than 10 minutes), so I gave Eraser another go. It looked like it got further than ever before - probably about 75% through the folder scanning process. But then it crashed again, and unlike before, the device was (temporarily) frozen - really as if something is hogging the CPU. A little later it spontaneously rebooted again, and it seems back into state 2 now. Grrr!


PS: The following may (or may not) be relevant to the above. Since the device started playing up, it seems to get itself into one of three states:

1. relatively stable: with apps apparently usable (except Messaging and Facetime - this is where the original problem arose as far as I can see), and remaining in this state for a long time when nothing in particular is attempted (e.g. I had an internet radio app play for several hours without a problem).
2. unstable: the device appears to be frozen for several seconds at a time, every so often. This can also be seen by the second hand of the clock app icon stalling. The device reboots spontaneously after at most a few minutes, even if no app is ever launched.
3. Unusable: the device boots to the lock screen, but swiping fails to bring up the unlock screen, and the time display is frozen too. After a few minutes, it reboots spontaneously.

Manually rebooting, including switching off (either through pressing the sleep/wake button and then "swiping to power off", or through the control centre's Shutdown button) eventually gets it back into state 1, although I have not discovered a way that systematically achieves this. It seems to be hit and miss.

When I attempted to run Eraser as described above, the device had been in state 1 for more than 12 hours, with the only thing happening the regular popping up of the "iMessage - Your carrier may charge for...(etc)" message.

 

[Koenfucius]

Just one quick addition. The underlying problem with the device I am seeking to solve seems to be related to messaging. When I put the phone in Airplane mode and re-enable WiFi the recurring "iMessage - your carrier..." stops appearing altogether, and there would seem to be no bouts of 'freezing'. So I thought I'd try to run Eraser in this 'semi'-airplane mode (i.e phone off, but WiFi on). No luck, though - it crashes out as before...

 

[Koenfucius]

The device had been 'stable' for about 24 hours so I thought I'd give it another go. This time Eraser went to 80%... 90%... 95% (or thereabouts) of the scanning process... and then crashed out again.

Maybe this one additional observation has some significance: after Eraser has crashed, the device becomes unstable again and enters a boot loop where it boots to the lock screen and either reboots again from there, or allows unlocking but then reboots within a minute or so from the home screen. Also, it looks as if a reasonably predictable way of getting it to boot into its 'stable' mode (see top message in this thread) is to switch it off, unplug the charger cable, leave for a little while, and then plug in the cable which wakes it up (and makes it boot without looping).

But I am beginning to come to terms with the fact that I will permanently lose the jailbreak on this device.

Unless someone comes up with some ideas on how to get Eraser to do its thing before it crashes out, I will close my eyes, shed a tear, and restore this device to 9.3.5 in the next couple of days...

 

[Koenfucius]

Sorry to keep on commenting to my own thread, but perhaps my live-blogging triggers something in someone's mind!

Just tried again and this time Eraser went way further than before, but eventually still crashed unfortunately. It seems to have interfered with installed jailbreaks - the time at the top, though shown correctly on the clock icon, shows PDT instead of London time (BST), and CCSettings seem to be missing (I don't know what the control center normally shows, since all my devices are jailbroken, but it doesn't show the respring/restart/power down icons).

One thing that occurs to me: as this is my old phone it has tonnes of apps that I never bothered to remove when giving it to my wife, and that seems to take a lot of the Eraser time. Perhaps I should clean up the iphone and remove all the apps - in fact, since it'll be erased anyway, I guess it doesn't matter if I remove all apps, as I will have to restore from a backup anyway.

Is this likely to help, anyone?

Thanks in advance!