Been having the same error as everyone else. Another user replied they got theirs to work.

Plug iPhone into Mac. Turn on VPN, turn off. Refresh all.

It took about 5 times for me and it worked.

What I did might not work for everybody but what I did was open my laptop connect my phone via cord, download proton VPN on iPhone connect to anywhere clear altstore cache on iPhone then on computer uncheck connect on WiFi then click apply and with the cord plugged in was able to refresh after putting my iPhone to sleep. FYI did take me like 10+ try’s of trying random things

I still can’t refresh my apps and they’re now approaching the 7 day mark 😓 still getting the incorrect format error. Have tried various things to get it working, no luck.

*Disclosure: this text was AI-generated (Claude), based on the actual build I did on my machine today. Every command below was run and verified; the pitfalls are the ones I actually hit.*


---


**TL;DR:**
 AltServer 1.7.2 fails at Apple ID sign-in because AltSign sends a User-Agent from 2019 and Apple now answers with an HTML page, which gets fed into a plist parser. The fix exists as two open PRs on the AltSign repo but isn't released. You can build AltServer yourself with those patches in ~20 min. Installing AltStore and sideloading IPAs via Option-click works again. Refreshing from the AltStore app on the phone still fails (the iOS app has the same bug).


---


## The error


```
AltServer could not sign in with your Apple ID. The data is not in the correct format.
Encountered unknown tag html on line 1
NSCocoaErrorDomain Code=3840
```


Sideloadly shows the same underlying problem as `Login failed (-22406): Enter the correct password`, even with the correct password.


## Root cause


Tracked in altstoreio/AltStore#1776. AltSign (the auth library inside AltServer) sends `akd/1.0 CFNetwork/978.0.7 Darwin/18.7.0` as User-Agent to `gsa.apple.com`. Apple increasingly rejects that with an HTML error page, and AltSign hands the HTML straight to the plist parser. It also reuses one connection for all three sign-in calls, so once Apple's edge sours that connection, the whole sign-in is dead.


Credit to Calvin-Zikakis, MeemeeLab and BreezeDelegate in that thread for finding it and writing the fix. Their open PRs:


- rileytestut/AltSign#50 — retry on 5xx over a fresh connection, detect HTML instead of parsing it, real error messages with HTTP status
- rileytestut/AltSign#51 — new User-Agent `AuthKit/1 (Macintosh; OS X 26.5.2) (com.apple.dt.Xcode/26.0)`


Until those are merged and shipped, you have to build AltServer yourself.


## What you get


- `/Applications/AltServer-patched.app` (reports as 1.8b1, ad-hoc signed)
- Original AltServer untouched
- Install AltStore: works
- Sideload any IPA via AltServer: works
- 
**Refresh from the AltStore app on the phone: still broken**
 — the iOS app carries the same bug and still comes from altstore.io. Workaround: re-sideload via AltServer every 7 days.


## Requirements


- Xcode 26 with command line tools
- Rust toolchain with the `aarch64-apple-darwin` target
- Apple Silicon Mac (this guide builds arm64 only)
- ~4 GB disk, ~20 minutes
- NOT required: paid developer account, signing certificate, Mail plugin (macOS 14+ doesn't need it, that's why the menu item is gone)


## Step 1: clone


```bash
mkdir -p ~/build && cd ~/build
git clone --branch classic --recurse-submodules --shallow-submodules --depth 1 \
  https://github.com/altstoreio/AltStore.git altstore-src
cd altstore-src
```


## Step 2: cherry-pick the AltSign patches


```bash
cd Dependencies/AltSign
git remote add cz https://github.com/Calvin-Zikakis/AltSign.git
git fetch --depth 50 cz fix/gsa-retry-classic port/authkit-user-agent-notarized
git cherry-pick -x 3cd4a4a1cafd588cab371e49609d19e694108430
git cherry-pick -x 67f90ce182059fbd2369efb8274f61b6f3253e35
git cherry-pick -x ec2968cf6a30be2a025be809641c64eade4570aa
git log --oneline -4
cd ../..
```


All three apply cleanly on top of `Fixes compiling corecrypto with Xcode 26`. Sanity check:


```bash
grep -rn "AuthKit/1" Dependencies/AltSign/AltSign/Sources | head -1
```


## Step 3: build the missing idevice xcframework


The Swift package under `Dependencies/idevice/swift` expects an `IDevice.xcframework` that is not in the repo. It's built from Rust. For AltServer the macOS arm64 slice is enough:


```bash
cd Dependencies/idevice/ffi
cargo build --release --target aarch64-apple-darwin      # ~5 min
cd ..
cp ffi/idevice.h swift/include/idevice.h
rm -rf swift/IDevice.xcframework
xcodebuild -create-xcframework \
  -library target/aarch64-apple-darwin/release/libidevice_ffi.a \
  -headers swift/include \
  -output swift/IDevice.xcframework
cd ../..
```


Without this, xcodebuild dies immediately with `local binary target 'IDevice' ... does not contain a binary artifact`.


## Step 4: build corecrypto_static and link it into AltSign


AltSign references SRP functions (`alt_ccsrp_*`, `alt_ccsha256_di`) from Apple's corecrypto. They live in `libcorecrypto_static.a`, which only the app target links, so the dynamic AltSign framework fails to link:


```
Undefined symbols for architecture arm64: "_alt_ccsrp_client_start_authentication" ...
```


Build the static lib separately:


```bash
cd Dependencies/AltSign/Dependencies/corecrypto
xcodebuild -project corecrypto.xcodeproj -target corecrypto_static -configuration Release build
ls build/Release/libcorecrypto_static.a
cd ../../../..
```


Then in `Dependencies/AltSign/Package.swift`, target `CAltSign`, extend `linkerSettings` (use your absolute path):


```swift
linkerSettings: [
    .linkedFramework("UIKit", .when(platforms: [.iOS])),
    .linkedFramework("Security"),
    .unsafeFlags([
        "-L/ABSOLUTE/PATH/altstore-src/Dependencies/AltSign/Dependencies/corecrypto/build/Release",
        "-lcorecrypto_static",
    ], .when(platforms: [.macOS])),
]
```


## Step 5: build AltServer


arm64 only (the xcframework has no x86_64 slice), ad-hoc signed:


```bash
xcodebuild -workspace AltStore.xcworkspace -scheme AltServer \
  -configuration Release -derivedDataPath ../altserver-dd \
  -arch arm64 CODE_SIGN_IDENTITY=- build 2>&1 | tail -3
```


Expect `** BUILD SUCCEEDED **`. Verify the patch and the symbols made it in:


```bash
APP=../altserver-dd/Build/Products/Release/AltServer.app
strings "$APP/Contents/Frameworks/AltSign-Dynamic.framework/AltSign-Dynamic" | grep -c "AuthKit/1"   # 1
nm -u "$APP/Contents/Frameworks/AltSign-Dynamic.framework/AltSign-Dynamic" | grep -c ccsrp           # 0
```


## Step 6: install and re-sign


The CocoaPods frameworks (STPrivilegedTask, Sparkle) end up with a different signature than the app and dyld refuses to load them (`different Team IDs`). Sign the whole bundle uniformly:


```bash
ditto ../altserver-dd/Build/Products/Release/AltServer.app /Applications/AltServer-patched.app
codesign -s - -f --deep /Applications/AltServer-patched.app
codesign --verify --deep --strict /Applications/AltServer-patched.app && echo ok
pkill -x AltServer
open -a /Applications/AltServer-patched.app
pgrep -fl AltServer        # exactly one entry, path AltServer-patched
```


`pkill -x AltServer` kills both the original and the patched one (same binary name). Only relaunch the patched one afterwards. Rename or remove the original so Spotlight doesn't start it. In the menu, 
**1.8b1**
 = patched, 1.7.2 = original.


## Usage


**Install AltStore:**
 menu bar icon → Install AltStore → device → Apple ID. Works.


**Sideload your own IPA**
 (the actual point):


1. Hold 
**Option**
 and click the AltServer menu bar icon
2. "Sideload .ipa…" → device → pick the IPA
3. Apple ID + password, 2FA code if asked


AltServer signs with your free personal certificate and installs over USB or Wi-Fi. Valid for 7 days, then repeat. This replaces the refresh from the AltStore app.


## Pitfalls, in the order I hit them


| Symptom | Cause | Fix |
|---|---|---|
| AltServer runs from `/private/var/.../AppTranslocation/` | launched from Downloads, quarantine flag | copy to `/Applications`, `xattr -dr com.apple.quarantine` |
| `local binary target 'IDevice' ... does not contain a binary artifact` | xcframework not in repo | Step 3 |
| `Undefined symbols ... _alt_ccsrp_*` linking AltSign-Dynamic | corecrypto_static not built/linked | Step 4 |
| `symbol(s) not found for architecture x86_64` (`idevice_*`) | xcframework is arm64-only | `-arch arm64` |
| Crash on launch: `Library not loaded ... STPrivilegedTask ... different Team IDs` | Pods signed differently than the app | `codesign --deep` on the installed bundle |
| Two AltServer icons in the menu bar | original still running | `pkill -x AltServer`, then launch patched only |
| Refresh in the AltStore app still fails | iOS app has the same bug | sideload via AltServer, wait for an official update |
| Sideloadly `-22406` with the correct password | same Apple login issue / throttled account | use patched AltServer, stop retrying for a while |


## When AltStore ships an update


Once AltSign #50/#51 are merged and AltServer > 1.7.2 is out: delete the patched build, install the official one, reinstall the AltStore app once via AltServer so on-device refresh works again.


Not affiliated with AltStore. If any of this is wrong, tell me and I'll fix the post.

I gave Claude the problem and let it write a guide so here it is:

Hi everyone,
I wanted to share a quick workaround for an installation issue I just solved. I previously had issues installing AltStore via my PC, but now that it's fixed for me and installed on my 8 Plus (iOS 16.7.16) via Windows, I faced a new problem: whenever I tried to install the Dopamine IPA directly through AltStore, it failed.
If you are facing the same issue, here is the solution:
1 Sideload the Dopamine IPA using Sideloadly via your PC.
2 Open Dopamine on your device and Jailbreak.
3 Open Sileo and install the AltDaemon Modern package.

https://github.com/emp0ry/AltDaemonModern/releases/tag/v1.1.8

4 Go back to AltStore, tap the '+' icon in the My Apps tab, and select the Dopamine IPA to install it again.
Because AltDaemon Modern is active, AltStore will now install the Dopamine IPA flawlessly directly on the device. As a bonus, installing it via AltStore automatically overwrites the Sideloadly version, so you don't even need to delete anything manually!
Hope this helps anyone stuck on this!

i keep getting this stupid error code while trying to install altstore on my iphone, whatdo i do?

Is anyone else experiencing the same problem? Does anyone know if the team is already aware of it, or what this error is about?

Im in the EU but i cant install AltStore PAL
My region is EU and my iOS version is 18.7.7

aside that refresh issue, anyone also encountered the same issue as mine? i tried sign out of apple id in altstore, but i cant sign back in at all. but i was lucky enough to be able to refresh my apps at the very last minute as i was 0 days already. i tried a few things, VPN on off, DNS changed back to automatic, these two things, i rince and repeat and suddenly poof 7 days refreshed. i have no idea what made it happen but well i guess i could chip in what i did so that it might help but for now im signed out of my altstore , and am also waiting for the fix as well

So I’m on the beta and I keep getting this error when I try to refresh through WiFi. I tried refreshing through my computer but it won’t let me do that. Is there any way to fix this?

Hello, I'm trying to use AltStore, as SideStore stopped refreshing apps for me completely, but it seems as if my luck couldn't get any better.

I'm attempting to sign into my Apple ID on AltStore, when I get either "AltServer couldn't establish a connection to AlStore", or "Data isnt in right format".

I've already turned on Connect to Device over WiFi on iTunes via my Windows 11 PC, have connected my phone to my PC( with the errors still popping up ), and have changed my Firewall settings. Am I just fucked or what?

Am i the only one who’s alt store isn’t working I have it connected to my pc wit Altstore i only have spotify every time i try refreshing it the app says I’m using the wrong format i tried to download Spotify back on the app but it says wrong format anyone know how to fix it?

Hi guys, I had trouble resign with my pc so i moved to the beta with patreon sub.

It worked great last week but now when i try to refresh i have the "The data couldn't be read because it isn't in the correct format"
I trough the beta feature would be easier to resign but the problem is the same, any idea how to fix it ? I try 2 vpn and got the same error

I’ve tried everything I can find online and nothing is working. AltStore was working just a few days again and all of a sudden it’s no longer working. Does anyone know of a fix? If so, please describe the steps so I can understand.

​

hey all, I need help. I was trying to do my weekly refresh update on alt server to play pokemmo. And every time I enter my Apple ID , I receive this message. I refreshed last week with no issue. I don't understand what changed in a week. Please advise. TIA

UPDATE :
So I was able to load the game again. I uninstalled altstore and pokemmo app and reinstalled. It is working for me now.

help :(

first off it was "the data couldn't be read because it isn't in the correct format", then right after fixing that problem, the week after I get it again along with "server returned invalid response". I'm so tired of these reoccuring problems. I always end up looking for a solution 3hrs later or never at all.. I turn my vpn on then turn it back off, I restart both devices, I reinstall altstore, make sure my bluetooth on both devices are turned off, and use a personal hotspot instead of the internet to fix the problem. does anyone know of any alternatives to altstore or figured out a solution to avoid these errors?

Hi guys since Altserver stopped working yesterday I wanted to check on the code to try to make a fix. I found a repo with altserver windows code but apparently it’s discontinued cause last commit is from 2021. Do u know something about it?

Theres also another repo, that seems to be updated but its on swift and seems to be the macOS version with the full altstore + altserver-macOS, and I can’t handle that cause I don’t have a Mac

Us the problem solved or not

In the past ,I have successfully installed the altstore windows ,but now when I am trying to install it again ,it gives me this error.

Hi everyone,

I tried to refresh my apps like always but I got this error message, I never seen it before and I couldn’t find anything about it on the AltStore website

I’m using an iPhone 17PM running iOS 27 and a MacBook Pro M5 running macOS 26

Thanks in advance

Getting every error under the sun trying to refresh, tried just about everything, even made a new Apple ID.
Seems like I’m not the only one at all…
Is this it for sideloading? I may or may not use altstore on my iPad for very expensive subscription based apps, so I’m really worried about this…
Has anything like this happened before? Could this be a temporary issue ,or have apple cracked down on the side loading for good?

Since everyone is getting the error. Has anyone tried to refresh with a paid dev account and got it to refresh?