I recently updated both my Mac and iPhone to version Tahoe 26.0. Since then, I have been unable to run my apps on iOS built using UE5.4.4. This is the case whether I use Xcode 16.4 or version 26.0; the apps crash right after starting. I tested this with a new third-person view app created from the template. I tried to debug it in Xcode, too: when I open the generated xcodeproj file in Xcode and start the app from there, I receive the following error message:
“libc++abi: __cxa_guard_acquire detected recursive initialization: do you have a function-local static variable whose initialization depends on that function?
__cxa_guard_acquire detected recursive initialization: do you have a function-local static variable whose initialization depends on that function?”
UE5.6 works well on Tahoe 26.0 with Xcode 16.4. However, I cannot use UE5.5 or UE5.6 for my projects until issue UE-265363 has been fixed. Now I cannot use UE5.4 either.
Can anyone suggest a solution or workaround to enable me to build and run a UE5.4 project on Tahoe 26.0?
Update: There is a case where an app cooked and packaged with UE5.4 works on iOS 26.0 devices. If one turns on the “For Distribution” switch in Project Settings, Project, Packaging, and sets the Build Configuration to Shipping, the app installed from the generated xcarchive file runs without any problems on both iOS 26.0 and 18.6. If “For Distribution” is false, it crashes on 26.0.
Did you manage to find a solution for this? I’m having the same issue with iOS 26. Lightbake only works on 5.4 and 5.5 (On Mac); however, both versions have this issue. I packaged a project made in 5.7, and Xcode didn’t give me the “__cxa_guard_acquire detected recursive initialization” error.
I had the same problem. Migrating the project to UE5.6 fixed it for me. It seems that older versions do not properly compile for iOS 26 with the latest Xcode but this is just my theory.
I tried upgrading my project to 5.7 and spent the better part of 2 days trying to get it to compile. I get over 120 errors like GEngine not being recognized, AActor being an unknown class etc etc etc. So I went back to 5.5 and there the errors all vanish but when I build my app hangs during the boot screen with the OP errors showing in Xcode.
Upgrading clearly doesn’t work and neither does downgrading yet Apple has given me until Jan 31 to push an update of my app with new age restriction questions answered and some other manner of nonsense that really could have been done without a new binary upload…. so what are my options? Apple says that if I don’t upload a new binary by 31 Jan then I lose the ability to make future updates yet [this] so what am I to do?
hi , @JansenSensei , have you tried UE-5.7.1 ? EPIC have refactory metal RHI on the latest UE version, I have tested some apps on iOS and Android on UE-5.8.0 , they all run well
Hi, yes. Sorry, I should have been more specific, yes, 5.7.1 gave me all those errors where it can’t find the basic UE classes like AActor. Spent two days trying to convert the project before finally giving up
