4.18.3 Crash on deploy to iOS devices

My team is working on a pair of projects for iOS. One of them works fine, but the other one, on deployment, crashes the editor with this message and stack trace:


FGenericPlatformMisc::RaiseException(unsigned int) Address = 0x10690499b (filename not found) [in UE4Editor-Core.dylib]
FMacErrorOutputDevice::Serialize(wchar_t const*, ELogVerbosity::Type, FName const&) Address = 0x10c744c19 (filename not found) [in UE4Editor-ApplicationCore.dylib]
FOutputDevice::Logf(wchar_t const*, ...) Address = 0x106bb2c9d (filename not found) [in UE4Editor-Core.dylib]
FDebug::AssertFailed(char const*, char const*, int, wchar_t const*, ...) Address = 0x106b28efb (filename not found) [in UE4Editor-Core.dylib]
FShaderCompilingManager::ProcessCompiledShaderMaps(TMap<int, FShaderMapFinalizeResults, FDefaultSetAllocator, TDefaultMapHashableKeyFuncs<int, FShaderMapFinalizeResults, false> >&, float) Address = 0x109167162 (filename not found) [in UE4Editor-Engine.dylib]
FShaderCompilingManager::FinishCompilation(wchar_t const*, TArray<int, FDefaultAllocator> const&) Address = 0x10916e9b6 (filename not found) [in UE4Editor-Engine.dylib]
FMaterialShaderMap::Compile(FMaterial*, FMaterialShaderMapId const&, TRefCountPtr<FShaderCompilerEnvironment>, FMaterialCompilationOutput const&, EShaderPlatform, bool, bool) Address = 0x108bd0f8c (filename not found) [in UE4Editor-Engine.dylib]
FMaterial::BeginCompileShaderMap(FMaterialShaderMapId const&, EShaderPlatform, TRefCountPtr<FMaterialShaderMap>&, bool) Address = 0x108beeb3b (filename not found) [in UE4Editor-Engine.dylib]
FMaterial::CacheShaders(FMaterialShaderMapId const&, EShaderPlatform, bool) Address = 0x108bedf97 (filename not found) [in UE4Editor-Engine.dylib]
FMaterial::CacheShaders(EShaderPlatform, bool) Address = 0x108bedb96 (filename not found) [in UE4Editor-Engine.dylib]
UMaterial::CacheShadersForResources(EShaderPlatform, TArray<FMaterialResource*, FDefaultAllocator> const&, bool) Address = 0x108ab25d6 (filename not found) [in UE4Editor-Engine.dylib]
UMaterial::CacheResourceShadersForCooking(EShaderPlatform, TArray<FMaterialResource*, FDefaultAllocator>&) Address = 0x108ab3312 (filename not found) [in UE4Editor-Engine.dylib]
UMaterial::BeginCacheForCookedPlatformData(ITargetPlatform const*) Address = 0x108ab7a01 (filename not found) [in UE4Editor-Engine.dylib]
UCookOnTheFlyServer::BeginPackageCacheForCookedPlatformData(UPackage*, TArray<ITargetPlatform const*, FDefaultAllocator> const&, FCookerTimer&) const Address = 0x10dd0390d (filename not found) [in UE4Editor-UnrealEd.dylib]
UCookOnTheFlyServer::SaveCookedPackages(TArray<UPackage*, FDefaultAllocator>&, TArray<FName, FDefaultAllocator> const&, TArray<ITargetPlatform const*, FDefaultAllocator> const&, FCookerTimer&, int, unsigned int&, unsigned int&) Address = 0x10dd06963 (filename not found) [in UE4Editor-UnrealEd.dylib]
UCookOnTheFlyServer::TickCookOnTheSide(float, unsigned int&, ECookTickFlags) Address = 0x10dcf68ef (filename not found) [in UE4Editor-UnrealEd.dylib]
UCookOnTheFlyServer::Tick(float) Address = 0x10dcf32d0 (filename not found) [in UE4Editor-UnrealEd.dylib]
UEditorEngine::Tick(float, bool) Address = 0x10df4a544 (filename not found) [in UE4Editor-UnrealEd.dylib]
UUnrealEdEngine::Tick(float, bool) Address = 0x10ebd4acc (filename not found) [in UE4Editor-UnrealEd.dylib]
FEngineLoop::Tick() Address = 0x1067f8fc5 (filename not found) [in UE4Editor]
GuardedMain(wchar_t const*) Address = 0x1068027a2 (filename not found) [in UE4Editor]
-[UE4AppDelegate runGameThread:] Address = 0x10680fe40 (filename not found) [in UE4Editor]
-[FCocoaGameThread main] Address = 0x106aaed17 (filename not found) [in UE4Editor-Core.dylib]
Unknown() Address = 0x7fff34f851f8 (filename not found) [in Foundation]
_pthread_body Address = 0x7fff5b4b9661 (filename not found) [in libsystem_pthread.dylib]
_pthread_body Address = 0x7fff5b4b950d (filename not found) [in libsystem_pthread.dylib]
thread_start Address = 0x7fff5b4b8bf9 (filename not found) [in libsystem_pthread.dylib]

We’re at a bit of a loss. Installing the engine’s debugging symbols did not make any difference.

Both of our apps use a combination of Blueprints and C++. The only significant difference I can think of for the one that’s throwing this error is that it is also using the gameDNA RealtimeDatabase and UltimateMobileKit plug-ins. However, I don’t see any indication in the stack trace that would point me toward those as the culprits.

The last thing I see in the output log before the crash is that there’s a missing cached shader map for material MatineeCam_mat and that it is compiling.

Anyone have any tips?