[Android][Mover] Crash in libUnreal.so at FInstancedStruct::Reset() - SIGSEGV / null pointer dereference on GameThread

Summary

We are seeing a native crash on multiple Android devices in the Google Play build.

The symbolicated crash trace points to FInstancedStruct::Reset(), with Mover and Network Prediction destructors in the stack.

Platform: Android / arm64
Distribution: Google Play
Build: Shipping
Engine: Unreal Engine 5.8.x

No assumption about the root cause is being made here. This report is based on the captured Android crash logs and symbolicated native stack trace.

What Type of Bug are you experiencing?

Platform Mobile

Steps to Reproduce

There is no specific way to reproduce that. It just randomly happens during the game on many devices

Expected Result

No crash

Observed Result

Android crash log:

Fatal signal 11 (SIGSEGV), code 1 (SEGV_MAPERR)
fault addr 0x00000000000002f8
Cause: null pointer dereference
Thread: GameThread
ABI: arm64
Library: libUnreal.so

The captured crash has:

#00 [libUnreal.so] FInstancedStruct::Reset()

The same crash signature appears repeatedly in the Android logs with:

SIGSEGV
SEGV_MAPERR
fault addr 0x2f8
GameThread
libUnreal.so

Affects Versions

5.8

Platform(s)

Android

For crash reports, include your callstack

[libUnreal.so] FInstancedStruct::Reset()
[libUnreal.so] FMoverUserDefinedDataStruct::~FMoverUserDefinedDataStruct()
[libUnreal.so] TModelDataStore<FMoverActorModelDef>::~TModelDataStore()
[libUnreal.so] FNetworkPredictionServiceRegistry::~FNetworkPredictionServiceRegistry()
[libUnreal.so] UNetworkPredictionWorldManager::~UNetworkPredictionWorldManager()
[libUnreal.so] FObjectPurge::DestroyObjects()
[libUnreal.so] IncrementalPurgeGarbage()
[libUnreal.so] CollectGarbage()
[libUnreal.so] UEngine::TrimMemory()
[libUnreal.so] UEngine::LoadMap()
[libUnreal.so] UEngine::Browse()
[libUnreal.so] UEngine::TickWorldTravel()