iOS 26 – Build succeeds after manually changing Max SDK version, but app crashes on launch

Development Platform & Builds Mobile
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1

Hey everyone,

I’ve been struggling with getting my Unreal Engine iOS build to run on iOS 26 / Xcode 26.0.1. I managed to get the project to build successfully, but the app crashes immediately on launch in both the simulator and on-device.

Here’s the full story so far:

  • I’m on macOS 15.6.1 with Xcode 26.0.1 (17A400).

  • Unreal Engine initially refused to build because it didn’t recognize the iOS 26 SDK version.

  • To get past that, I manually edited the Unreal iOS configuration file (the one that defines supported SDK versions) and increased the MaxVersion for iOS, that allowed the build to complete successfully.

However, the app fails to launch and the simulator log shows this error:

Domain: FBSOpenApplicationServiceErrorDomain

Code: 1

Failure Reason: The request was denied by service delegate (SBMainWorkspace).

The full error message also includes:

The process failed to launch.

Launchd job spawn failed

Domain: NSPOSIXErrorDomain

Code: 163

From my research, it looks like iOS 26 enforces the UIScene lifecycle, which Unreal’s iOS integration might not yet fully support. I also tried adding a minimal UIApplicationSceneManifest block in the Info.plist, but the issue persists.

Has anyone else encountered this when running Unreal apps on iOS 26?
Is there a proper workaround or upcoming engine fix for this?

Thanks in advance!

System setup:

  • macOS: 15.6.1 (24G90)

  • Xcode: 26.0.1 (17A400)

  • Unreal Engine: [insert your version here]

  • iOS SDK: 26.0

• Device/Simulator: iPad16,4 (iOS 26.0)

2

Have the same issue. Can’t find a valid solution online. Could you find what’s causing this and how to fix it?

3

I just tested building official demo “CropoutSampleProject” on Mac Tahoe-26.0.1 with xcdoe-26.0.1 for iOS-18.7.1 , i am using UE-5.8.0 , it runs well on my iphone 12pro.

4

I realased an app for real estate and my client just updated to iOS 26, which totally breaks the app. I’ve been looking for info about how to fix this and stop the crash but not luck yet. Any clue?

5

After update mac and iphone to 26.1 , update source code to today’s commit, unreal app now can be run on iphone ….

but after some minutes , unreal app was terminated because it ate up all memory .

6

I’m having the same issue with my app
UE 5.4
Xcode 16.0
iOS18 - runs fine
iOS26 - crashes on launch

I’ve tried a couple of different Xcode versions, including xcode26, and get the same result.

I’m now testing using the FirstPerson sample project and i’m seeing the same behavior.

I found this post, which sounds like a fix may come in UE5.7. But this doesn’t help me as i really need to stay on UE5.4

If this is indeed the issue, then it should affect anyone trying to build for iOS in UE5.4, 5.5, & 5.6?

7

are you running UE5.7 preview?

8

i am on UE-5.8

9

ok, that makes sense as it looks like the fix went in on 5.7.

-e

10

ok… i’m starting to get a better picture of the issue.
in my testing using the First Person project and Quick Launch on device and Xcode 16.2

  • UE5.2 iOS 26 good
  • UE5.4 iOS 26 crash
  • UE5.5 iOS 26 crash
  • UE5.6 iOS 26 good

This doesn’t quite make sense as the commit that i thought was fixing the issue doesn’t appear to have gone into 5.6. I went and looked GitHub and that change did not get into 5.6. So that commit is not really the fix.

But something broke in 5.4 and got fixed in 5.6 that affects crashing on iOS26