UE 4.25.1 crashing at startup on iOS 18.4 - continued

Development Platform & Builds Mobile
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This question was created in reference to: [UE 4.25.1 crashing at startup on iOS [Content removed]

I work with the same project that the question above pertains to and the fix seemed to work for a few days, but when iOS 18.4.1 released our crash rates skyrocketed again. So far we don’t have enough data from iOS 18.5 to see if it has improved or worsened the situation, but we are not expecting miracles.

To reiterate, the game crashes on startup during engine initialization, and the few crash logs we can retrieve all end like this:

Crashed: Thread 0 libsystem_kernel.dylib 0x6bbc __pthread_kill + 8 1 libsystem_pthread.dylib 0xd854 pthread_kill + 208 2 libsystem_c.dylib 0x1f6ac abort + 124 3 Proj_UE4 0x22b7990 FGenericPlatformMallocCrash::InitializeSmallPools() + 468 (GenericPlatformMallocCrash.cpp:468) 4 Proj_UE4 0x23be92c FIOSErrorOutputDevice::Serialize(char16_t const*, ELogVerbosity::Type, FName const&) + 29 (IOSErrorOutputDevice.cpp:29) 5 Proj_UE4 0x244d4d8 FOutputDevice::LogfImpl(char16_t const*, ...) + 159 (UnrealMemory.h:159) 6 Proj_UE4 0x23fd6b4 FDebug::CheckVerifyFailedImpl(char const*, char const*, int, char16_t const*, ...) + 463 (ContainerAllocationPolicies.h:463) 7 Proj_UE4 0x5b1f798 UProjTime::IsWithinTimeframe(long long, long long) (.cold.1) + 90 (ProjTime.cpp:90)The previous solution was setting both SmallBlockStartPtr and SmallBlockEndPtr in FMallocBinned to 0.

Has any information about changes in iOS memory handling surfaced, or if Unreal 4.25.1’s memory handling is incompatible with new version of iOS?

Any help would be greatly appreciated.

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Hi Filip,

Is there any obstacle to moving from 4.25.1 to the LTS release of 4.27+?

Best regards.

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Hi Stéphane,

We have done quite a few engine modifications, but as far as we can tell, no, there doesn’t seem to be any obstacles to moving to 4.27+. We have been hard at work to get it running on the updated engine the last few weeks, hopefully we’ll see some results soon.

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Sounds good Filip, keep us posted if there are any issues. 4.27+ should provide better compatibility going forward as it has recently been updated to support Xcode 16.3+ which brought a new version of clang.

Best regards.