AIR 51.3.2.2 iOS app crashes with “Packaging Error, please check your assets.car file”

Hi everyone,

I am currently having a critical issue with iOS packaging using Adobe AIR SDK 51.3.2.2 and would like to know if this is a known regression or if anyone has found a working solution.

Environment:

• Adobe AIR SDK: 51.3.2.2

• Adobe Animate

• Xcode 26

• iOS 18 / iPadOS 18+

• Pure AIR application (NO ANEs, NO distriqt extensions)

Problem:
If I package my app using a custom Assets.car, the app installs successfully on the iPad/iPhone, shows the splash/title screen for about one second, then immediately crashes with the message:

“Packaging Error, please check your assets.car file”

What I already tested:

• completely recreated Assets.car using Xcode

• all required icon sizes added correctly

• no transparency in PNGs

• valid 120x120 icon included

• Assets.car exists only once in the IPA

• file is located correctly in the app root

• CFBundleIconName set to AppIcon

• tested renderMode="gpu" and renderMode="direct"

• no ANEs used

• re-signing IPA manually

• tested on real devices

My AIR XML currently contains:

<iPhone>
    <assetsCar>Assets.car</assetsCar>
    <requestedDisplayResolution>high</requestedDisplayResolution>

    <InfoAdditions><![CDATA[
        <key>CFBundleIconName</key>
        <string>AppIcon</string>
    ]]></InfoAdditions>
</iPhone>

Important:
If I REMOVE Assets.car and instead use classic PNG icons inside the <icon> tag, the app works perfectly on the device.

However, App Store Connect / Transporter then rejects the IPA with:

“Missing required icon file. The bundle does not contain an app icon of exactly 120x120 pixels…”

even though the 120x120 PNG definitely exists and is correctly referenced.

So currently I am stuck between:

• Assets.car → App crashes

• classic PNG icons → Upload rejected by Apple

I also found multiple reports describing similar regressions in AIR 51.2.x / 51.3.x with iOS 18+:

• AIR apps crashing immediately after launch with “application packaging error”

• issues related to Assets.car packaging/runtime lookup

Examples:

• https://github.com/airsdk/Adobe-Runtime-Support/issues/4141

• https://github.com/airsdk/Adobe-Runtime-Support/issues/3932

Has anyone found a stable workflow for:

• AIR 51.3.x

• Xcode 26

• iOS 18+

• App Store compliant icon packaging?

Or is this currently a confirmed AIR runtime regression?

Any help would be greatly appreciated because at the moment it is impossible to both:

1. upload successfully to App Store Connect
   AND

2. launch the app successfully on-device.

Thanks!