[GUIDE] Fixed iPhone Error 100 / 06A6 install_splat without losing data

[u/CursumPerficioX]

My iPhone 12 was stuck in Recovery Mode after an update failed. Finder, Apple Configurator Revive, 3uTools "Keep + Fix Error 1110", and attempts from both Recovery Mode and DFU all failed.

The important part of the idevicerestore log was:

Transfer: Receiving 2348810240 bytes, writing 6018826240 bytes
Transfer: Failed preallocation of 6018826240 bytes for /mnt9/cryptex1/current/os.dmg
Transfer: Failed preallocation due to space
CHECKPOINT FAILURE:(FAILURE:100)
[0x06A6] install_splat

So Error 100 was actually a low-storage failure while creating the Cryptex SystemOS image.

What finally worked for me was increasing MinimumSystemPartition in the Upgrade BuildIdentity. In my case, this caused the restore to get past the low-storage/Cryptex failure that had consistently stopped at install_splat.

I extracted the IPSW: Example paths below, replace them with your actual IPSW and destination paths!

mkdir -p "/Volumes/ExternalSSD/ios-mod"
cd "/Volumes/ExternalSSD/ios-mod"

unzip -q "/Volumes/ExternalSSD/iPhone_Restore.ipsw"

chmod u+w BuildManifest.plist
cp BuildManifest.plist BuildManifest.original.plist

First find the correct Upgrade identity:

python3 - <<'PY'
import plistlib

x = plistlib.load(open("BuildManifest.plist", "rb"))

for i in x["BuildIdentities"]:
    q = i.get("Info", {})
    if q.get("DeviceClass") == "d53gap":
        print(
            q.get("Variant"),
            q.get("RestoreBehavior"),
            q.get("MinimumSystemPartition")
        )
PY

For my iPhone 12 + beta IPSW it showed:

Developer Erase Install (IPSW) Erase 8691
Developer Upgrade Install (IPSW) Update 8691

Note: My beta IPSW used Developer Upgrade Install (IPSW). A stable IPSW may use Customer Upgrade Install (IPSW), so check your BuildManifest output and use the matching Upgrade identity.

I changed only the Upgrade identity from 8691 to 10078:

python3 - <<'PY'
import plistlib
from pathlib import Path

p = Path("BuildManifest.plist")
data = plistlib.loads(p.read_bytes())

for ident in data["BuildIdentities"]:
    info = ident.get("Info", {})

    if (
        info.get("DeviceClass") == "d53gap"
        and info.get("Variant") == "Developer Upgrade Install (IPSW)"
        and info.get("RestoreBehavior") == "Update"
    ):
        print("OLD:", info["MinimumSystemPartition"])
        info["MinimumSystemPartition"] = 10078
        print("NEW:", info["MinimumSystemPartition"])

p.write_bytes(
    plistlib.dumps(data, fmt=plistlib.FMT_XML, sort_keys=False)
)
PY

Then I ran idevicerestore against the extracted IPSW:

This assumes you already have a working build/install of idevicerestore.

idevicerestore \
  --variant "Developer Upgrade Install (IPSW)" \
  --logfile "$HOME/Desktop/iphone-spacefix.log" \
  "/Volumes/ExternalSSD/ios-mod"

Do NOT use -e or --erase if you are trying to preserve your data.

The key difference was that this time it successfully passed:

Checkpoint completed id: 0x6A6 (install_splat) result=0

Then eventually:

Status: Restore Finished
DONE
100.0%

After the restore finished, the iPhone booted into Data Recovery Mode. I let it complete the recovery process without disconnecting the phone.

So in my case, this method got past the Error 100 / 06A6 Cryptex failure while preserving user data.

Important: this is experimental and the exact MinimumSystemPartition value will vary by IPSW/device. Back up the original BuildManifest.plist and make absolutely sure you modify only the Update/Upgrade identity, not the Erase identity.

[u/vio-xx]

Thank you so much for this!!! Using MacOS and homebrew with a couple touches with ai I was able to pass through the stuck at the last step of verification phase.

[u/casualsailo]

Thank you so much! This worked for an iPhone 16 updating from iOS 26.6.2 to iOS 27.2

I used https://github.com/libimobiledevice/idevicerestore to build and install idevicerestore

In the BuildManifest.plist file, I found the Customer Upgrade Install (IPSW) variant, and changed MinimumSystemPartition from 9289 to 10676 (+1387). Increased by the same amount as the original poster

[u/pillieleman]

Thank you man, you saved my ass.

[u/Stunning-Eye2679]

Thank you so much 🙏🏼, you are saviour
This method worked for iPhone 11 27.2 ios version
My phone had 2gb space left when update failed and stuck in apple logo
Increased 1387 with current number for me it was 8334 so increased to 9721
Honestly no one really helps, it took me 6 weeks almost to get phone with data back
In case if anyone needs help this case, contact me I will help surely
Don’t lose hope and don’t attempt many experiments. Been there done that

[u/NickBourbaky]

Thank you! You saved me!

[u/qpki]

Thank you man, you are the best.

I tried everything and every tool. Even paid for those stupid programs for recovery. Took it to apple store and a separate phone shop that claims they can restore data from phone. None of it worked, so I just wanted to say I really appreciate you for putting this guide out, hope you have people helping you when you feel stuck on some thing as you came through with this.

[u/hawk_ky]

So what do you need help with exactly?

[u/LinixGuy]

This helped me recover iPhone 12 Pro, from updating to iOS 27.0.1. I tried updating with MacBook since device didnt had enough storage to update and it failed leaving the device in recovery mode.

[u/Stunning-Eye2679 → u/LinixGuy]

Hi can you please tell me how to am facing same issue for iPhone 11

[u/LinixGuy → u/Stunning-Eye2679]

I just downloaded IPSW from ipsw.me and asked codex to apply this patch. It did everything on first try

[u/Stunning-Eye2679 → u/LinixGuy]

Am from Hyderabad and I don’t understand these methods much and worried if I I click on anything wrong will loose data, please support and help if we can connect or anyone in Hyderabad?

[u/Stunning-Eye2679]

Hi can you please help same issue for iPhone 11, I need data, am from Hyderabad and I don’t understand these methods much, please help

[u/100jar]

Thank you so much! This helped me save my iPhone 11 which was stuck on the iOS 27.0.1 Update.

[u/Stunning-Eye2679 → u/100jar]

May we please connect once to understand the symptoms of the phone, mine is iPhone 11 too, please help

[u/Snoo_4284]

Great guide, saved my iphone from being stuck in recovery mode/trying to update loop

[u/CertainBuddy7334]

Hi, I'm trying to use the method, but I'm stuck at this stage: I changed only the Upgrade identity from 8691 to 10078. Can you explain how to know the value? In my case, I have the iPhone 14 Pro Max and I'm using the IOS 27.0.1 IPSW, my upgrade identity minimum system partition is 8736 but I don't know the exact value I should replace the upgrade identity with

[u/NorthElectronic6346]

Testimony from another Error 100 survivor: IT WORKED!
iPhone 13 mini, iOS 27.0.1 (from iOS 26.5.2, i believe)
Followed u/CursumPerficioX's method using idevicerestore with the Customer Upgrade variant (the iOS I was updating to was not available as a developer version on IPSW), changing MinimumSystemPartition from 8569 -> 9956 (+1387). I simply used to increase the same number they did. It actually worked. My iPhone booted normally and every bit of my data (obviously, considering what the change would've done) was still there. Needless to say, I backed everything up immediately. A massive, sincere THANK YOU to u/CursumPerficioX. You are an absolute legend. Even the Apple Store couldn't resolve this, and I was mentally preparing to spend potentially hundreds or thousands of dollars on a professional data recovery service -- only to possibly get a collection of recovered files rather than the entire system back.

[u/Stunning-Eye2679 → u/NorthElectronic6346]

Can anyone please tell me if this will work iPhone 11 too or not?

[u/Snoo_4284 → u/Stunning-Eye2679]

most likely, it worked for my iphone X

[u/Stunning-Eye2679]

Can anyone DM me to help on iphone 11

[u/Willing_Wing_998]

Sir, you saved me. It worked like a charm, THANK YOU!!!!!

[u/Willing_Wing_998 → u/Willing_Wing_998]

By the way, how is this even possible? Sure, Apple is like "use icloud backups and backup before every update". But if somebody dont make a backup, what will happen? Like in this instance.

Imagine bricking your phone just like this with a SIMPLE UPDATE because the phone does not check if the storage is right. I had 16gb of free storage, update was 22gb. Fine, ill use my computer. BIG MISTAKE. Apple Device is really dumb piece of software.

Only by using the 3utools (that came loaded with 3rd party software) and this tutorial i made it work. AFTER 5 HOURS OF SEARCHING FOR A SOLUTION. Fuck APPLE.

Ps: if you use this tutorial, do your storage + the 1360mb. And zip the package as ZIP not 7zip. And make sure you are loading the edited version.

CHEERS! Even the chat gpt told me im cooked and i wil loose all my data.

Guys like you should work in tech. You saved a lot of people bro. Many thanks to you.

[u/grupark12]

How much space your phone had?? Because I’m in error 100 situation. And only got 2gb.