[IOS] Unity Crashes on Startup with Deep Link Launch EXC_BAD_ACCESS (code=1, address=0x378)

[Vitalchek]

Checklist

• I've updated to the latest released version of the Facebook SDK and also set previous versions
• I've changed Unity versions

Environment

• Unity 2022.3.14f1
• Xcode 15.2
• Facebook SDK Version 15.1
• MacOs - Sonoma
• Platform - IOS

Goals

The application was launched via a deep link

Expected Results

The application crashes at startup. When I tried to delete the Facebook SDK, everything works perfectly. This prom=blem only on IOS, Android works fine.

Before updating to Unity 2022 and updating macOs - Sonoma and Xcode 15, it worked perfectly.

Actual Results

Error

* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x378) frame #0: 0x00000001171ee5ec UnityFrameworkcore::StringStorageDefault::assign(char const*, unsigned long) + 28
frame #1: 0x000000011791c4b8 UnityFrameworkPlayerSettings::SetAbsoluteURL(core::basic_string<char, core::StringStorageDefault<char>> const&) + 44 frame #2: 0x000000011799e778 UnityFrameworkUnitySetAbsoluteURL + 108
frame #3: 0x00000001155073d8 UnityFramework-[UnityAppController application:openURL:options:] + 192 frame #4: 0x000000019905e724 UIKitCore__58-[UIApplication _applicationOpenURLAction:payload:origin:]_block_invoke + 1024
frame #5: 0x000000019905e174 UIKitCore-[UIApplication _applicationOpenURLAction:payload:origin:] + 788 frame #6: 0x000000019845c3d8 UIKitCore-[UIApplication _callInitializationDelegatesWithActions:forCanvas:payload:fromOriginatingProcess:] + 3256
frame #7: 0x000000019845b22c UIKitCore-[UIApplication _runWithMainScene:transitionContext:completion:] + 856 frame #8: 0x000000019845ae78 UIKitCore-[_UISceneLifecycleMultiplexer completeApplicationLaunchWithFBSScene:transitionContext:] + 132
frame #9: 0x00000001983d7798 UIKitCore_UIScenePerformActionsWithLifecycleActionMask + 112 frame #10: 0x000000019845ee74 UIKitCore__101-[_UISceneLifecycleMultiplexer _evalTransitionToSettings:fromSettings:forceExit:withTransitionStore:]_block_invoke + 216
frame #11: 0x0000000198386778 UIKitCore-[_UISceneLifecycleMultiplexer _performBlock:withApplicationOfDeactivationReasons:fromReasons:] + 220 frame #12: 0x00000001983851f0 UIKitCore-[_UISceneLifecycleMultiplexer _evalTransitionToSettings:fromSettings:forceExit:withTransitionStore:] + 608
frame #13: 0x0000000198384b58 UIKitCore-[_UISceneLifecycleMultiplexer uiScene:transitionedFromState:withTransitionContext:] + 248 frame #14: 0x0000000198384a28 UIKitCore__186-[_UIWindowSceneFBSSceneTransitionContextDrivenLifecycleSettingsDiffAction _performActionsForUIScene:withUpdatedFBSScene:settingsDiff:fromSettings:transitionContext:lifecycleActionType:]_block_invoke + 148
frame #15: 0x0000000198384930 UIKitCore+[BSAnimationSettings(UIKit) tryAnimatingWithSettings:fromCurrentState:actions:completion:] + 736 frame #16: 0x00000001983841b8 UIKitCore_UISceneSettingsDiffActionPerformChangesWithTransitionContextAndCompletion + 224
frame #17: 0x0000000198383e68 UIKitCore-[_UIWindowSceneFBSSceneTransitionContextDrivenLifecycleSettingsDiffAction _performActionsForUIScene:withUpdatedFBSScene:settingsDiff:fromSettings:transitionContext:lifecycleActionType:] + 316 frame #18: 0x0000000198707620 UIKitCore__64-[UIScene scene:didUpdateWithDiff:transitionContext:completion:]_block_invoke.225 + 612
frame #19: 0x0000000198382fec UIKitCore-[UIScene _emitSceneSettingsUpdateResponseForCompletion:afterSceneUpdateWork:] + 216 frame #20: 0x0000000198382e5c UIKitCore-[UIScene scene:didUpdateWithDiff:transitionContext:completion:] + 244
frame #21: 0x000000019849b484 UIKitCore-[UIApplication workspace:didCreateScene:withTransitionContext:completion:] + 508 frame #22: 0x000000019849b21c UIKitCore-[UIApplicationSceneClientAgent scene:didInitializeWithEvent:completion:] + 288
frame #23: 0x00000001ae2c76d4 FrontBoardServices-[FBSScene _callOutQueue_didCreateWithTransitionContext:completion:] + 324 frame #24: 0x00000001ae2c7570 FrontBoardServices__92-[FBSWorkspaceScenesClient createSceneWithIdentity:parameters:transitionContext:completion:]_block_invoke.108 + 280
frame #25: 0x00000001ae2c619c FrontBoardServices-[FBSWorkspace _calloutQueue_executeCalloutFromSource:withBlock:] + 168 frame #26: 0x00000001ae2d1f8c FrontBoardServices__92-[FBSWorkspaceScenesClient createSceneWithIdentity:parameters:transitionContext:completion:]_block_invoke + 352
frame #27: 0x000000019dfe5300 libdispatch.dylib_dispatch_client_callout + 20 frame #28: 0x000000019dfe8d48 libdispatch.dylib_dispatch_block_invoke_direct + 284
frame #29: 0x00000001ae2c2520 FrontBoardServices__FBSSERIALQUEUE_IS_CALLING_OUT_TO_A_BLOCK__ + 52 frame #30: 0x00000001ae2c24a0 FrontBoardServices-[FBSMainRunLoopSerialQueue _targetQueue_performNextIfPossible] + 240
frame #31: 0x00000001ae2c2378 FrontBoardServices-[FBSMainRunLoopSerialQueue _performNextFromRunLoopSource] + 28 frame #32: 0x000000019605f31c CoreFoundationCFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION + 28
frame #33: 0x000000019605e598 CoreFoundation__CFRunLoopDoSource0 + 176 frame #34: 0x000000019605cd4c CoreFoundation__CFRunLoopDoSources0 + 244
frame #35: 0x000000019605ba88 CoreFoundation__CFRunLoopRun + 828 frame #36: 0x000000019605b668 CoreFoundationCFRunLoopRunSpecific + 608
frame #37: 0x00000001d94265ec GraphicsServicesGSEventRunModal + 164 frame #38: 0x00000001984782b4 UIKitCore-[UIApplication _run] + 888
frame #39: 0x00000001984778f0 UIKitCoreUIApplicationMain + 340 frame #40: 0x000000011550bc0c UnityFramework-[UnityFramework runUIApplicationMainWithArgc:argv:] + 92`

[StrozhDima]

Confirm crashes at startup on SDK versions 15.1.0 and 16.0.2 and Unity 2022.3.16f1
UPD: The problem appeared in version 2022.3.13f. Version 2022.3.12f works without this problem.

[Vitalchek]

Great, thank you very much, I spent so much time. Thanks for the answer

[StrozhDima]

Unity issue link

[xTheEc0]

Seems like FacebookSDK issue.
FixColdStart() is a 9 year old addition, that now misbehaves.
Maybe in the past it worked, but now Unity trampoline function didFinishLaunchingWithOptions looks completely different, so this ends up editing one function below (isBackgroundLaunchOptions) by accident.

I think the whole regex replacement part can be deleted from FacebookSDK, if anyone wants to make a PR.

As a workaround: In the Xcode build, modify the Unity-iPhone/Classes/UnityAppController.mm isBackgroundLaunchOptions last line from return YES; to return NO;

Bad code:

- (BOOL)isBackgroundLaunchOptions:(NSDictionary*)launchOptions
{
    if (launchOptions.count == 0)
        return NO;

    // launch due to location event, the app likely will stay in background
    BOOL locationLaunch = [[launchOptions valueForKey: UIApplicationLaunchOptionsLocationKey] boolValue];
    if (locationLaunch)
        return YES;
    return YES; // <-- ISSUE HERE
}

Good code:

- (BOOL)isBackgroundLaunchOptions:(NSDictionary*)launchOptions
{
    if (launchOptions.count == 0)
        return NO;

    // launch due to location event, the app likely will stay in background
    BOOL locationLaunch = [[launchOptions valueForKey: UIApplicationLaunchOptionsLocationKey] boolValue];
    if (locationLaunch)
        return YES;
    return NO;
}

P.S It looks like Unity regression (You said 2022.3.12f1 -> 2022.3.13f1), but we just refactored our launch code around there recently, so FBSDK started modifying it randomly, which is the root cause.

[Nezz]

@xTheEc0 Was the change in the original code introduced in Unity 2022.3.13 or an earlier version?

[mutluerdm]

Thx @xTheEc0

build post process fix :

        [PostProcessBuild(10000)]
        public static void IOSBuildPostProcess(BuildTarget target, string pathToBuiltProject)
        {
        .
        .
            FixColdStartFacebook(pathToBuiltProject);  // Call this function from your IOSBuildPostProcess 
        .
        .
        }


        private const string IsBackgroundLaunchOptions = @"(?x)(isBackgroundLaunchOptions.+(?:.*\n)+?\s*return\ )YES(\;\n\})# }";

        public static void FixColdStartFacebook(string path)
        {
            string fullPath = Path.Combine(path, Path.Combine("Classes", "UnityAppController.mm"));
            string data = Load(fullPath);

            data = Regex.Replace(
                data,
                IsBackgroundLaunchOptions,
                "$1NO$2");

            Save(fullPath, data);
        }
        
        static string Load(string fullPath)
        {
            string data;
            FileInfo projectFileInfo = new FileInfo(fullPath);
            StreamReader fs = projectFileInfo.OpenText();
            data = fs.ReadToEnd();
            fs.Close();

            return data;
        }

        static void Save(string fullPath, string data)
        {
            System.IO.StreamWriter writer = new System.IO.StreamWriter(fullPath, false);
            writer.Write(data);
            writer.Close();
        }

[Vitaliy060795]

I launch Unity successfully from a deep link when I add this code in post process, but Application.absoluteURL is empty (

[Vitaliy060795]

@mutluerdm maybe do you know ? why does it happen ?

[Nezz]

The change in Unity 2022.3.13 that triggered the issue is the following:

iOS: Fixed Unity launching in the background on background location event; fix black screen showing between splash screen and first scene (release build only). (UUM-52515)

Affected versions:
2021.3.31f1
2022.3.11f1
2023.1.17f1
2023.2.0b14
2023.3.0a10

[Vitalchek]

@Nezz Is it possible to somehow fix it so that the game starts on unity
2022.3.14f1 version and reads the parameters from the deeplink?

[Nezz]

Yes, see #713