FLevelInstanceActorGuid::GetGuid issue in Multiplayer

I am doing some runtime manipulation of data layers and I am running into a check failure due to a zero guid in FLevelInstanceActorGuid::GetGuid during multiplayer testing.

When I debug FLevelInstanceActorGuid::GetGuid_Internal(), it is because Actor->HasAuthority() is false, because the execution at the time is being run on the simulated proxy, and when this occurs, GetGuid_Internal returns the cached FLevelInstanceActorGuid.ActorGuid.

This value seems to be serialized for PIE in the following function. Problem is, the level instance that is failing this check is nested in a data layer of another level instance, and so this code doesn't run on it.

I added some logs to confirm this hunch, and sure enough the only levels that this serialization code runs are the ones in the PersistentLevel, not anything nested within.

• Create a BP class that derives from Level Instance.
• Enable "Replicates" in the BP.
• Place this BP into a WP level with behavior as standalone.
• Create a new WP level for the BP level instance actor to reference.

• Enable Streaming.
• Add a runtime data layer that is initially unloaded.
• Add a standalone level instance that references a WP level with streaming enabled to the data layer.
• Set Net Mode as "Play as Client"

Assertion failed: Actor->IsTemplate() || Guid.IsValid() [...\Engine\Source\Runtime\Engine\Private\LevelInstance\LevelInstanceActorGuid.cpp] [Line: 25]

> UnrealEditor-Engine.dll!FLevelInstanceActorGuid::GetGuid() Line 25 C++
UnrealEditor-Engine.dll!FLevelInstanceActorImpl::OnLevelInstanceLoaded() Line 93 C++
UnrealEditor-Engine.dll!ULevelInstanceSubsystem::RegisterLoadedLevelStreamingLevelInstance(ULevelStreamingLevelInstance * LevelStreaming) Line 374 C++
UnrealEditor-Engine.dll!ULevelStreamingLevelInstance::OnLevelLoadedChanged(ULevel * InLevel) Line 554 C++
UnrealEditor-Engine.dll!ULevelStreaming::SetLoadedLevel(ULevel * Level) Line 1401 C++
UnrealEditor-Engine.dll!ULevelStreaming::PrepareLoadedLevel(ULevel * InLevel, UPackage * InLevelPackage, int InPIEInstanceID) Line 1468 C++
UnrealEditor-Engine.dll!ULevelStreaming::AsyncLevelLoadComplete(const FName & InPackageName, UPackage * InLoadedPackage, EAsyncLoadingResult::Type Result) Line 1784 C++
[Inline Frame] UnrealEditor-Engine.dll!Invoke(void(ULevelStreaming::*)(const FName &, UPackage *, EAsyncLoadingResult::Type) PtrMemFun, ULevelStreaming * &) Line 66 C++
[Inline Frame] UnrealEditor-Engine.dll!UE::Core::Private::Tuple::TTupleBase<TIntegerSequence<unsigned int>>::ApplyAfter(void(ULevelStreaming::*)(const FName &, UPackage *, EAsyncLoadingResult::Type) &) Line 320 C++
UnrealEditor-Engine.dll!TBaseUObjectMethodDelegateInstance<0,ULevelStreaming,void __cdecl(FName const &,UPackage *,enum EAsyncLoadingResult::Type),FDefaultDelegateUserPolicy>::ExecuteIfSafe(const FName & <Params_0>, UPackage * <Params_1>, EAsyncLoadingResult::Type <Params_2>) Line 689 C++
[Inline Frame] UnrealEditor-CoreUObject.dll!TDelegate<void __cdecl(FName const &,UPackage *,enum EAsyncLoadingResult::Type),FDefaultDelegateUserPolicy>::ExecuteIfBound(const FName &) Line 635 C++
[Inline Frame] UnrealEditor-CoreUObject.dll!FAsyncLoadingThread2::FCompletedPackageRequest::CallCompletionCallbacks() Line 3605 C++
UnrealEditor-CoreUObject.dll!FAsyncLoadingThread2::ProcessLoadedPackagesFromGameThread(FAsyncLoadingThreadState2 & ThreadState, bool & bDidSomething, TArrayView<int const ,int> FlushRequestIDs) Line 8501 C++
UnrealEditor-CoreUObject.dll!FAsyncLoadingThread2::TickAsyncLoadingFromGameThread(FAsyncLoadingThreadState2 & ThreadState, bool bUseTimeLimit, bool bUseFullTimeLimit, double TimeLimit, TArrayView<int const ,int> FlushRequestIDs, bool & bDidSomething) Line 8573 C++
UnrealEditor-CoreUObject.dll!FAsyncLoadingThread2::FlushLoading(TArrayView<int const ,int> RequestIDs) Line 10114 C++
UnrealEditor-CoreUObject.dll!FlushAsyncLoading(TArrayView<int const ,int> RequestIds) Line 348 C++
UnrealEditor-Engine.dll!UWorld::FlushAsyncLevelRequests() Line 4568 C++
[Inline Frame] UnrealEditor-Engine.dll!UWorld::FlushLevelStreaming::__l2::<lambda_1>::operator()() Line 4905 C++
UnrealEditor-Engine.dll!UWorld::FlushLevelStreaming(EFlushLevelStreamingType FlushType) Line 4912 C++
UnrealEditor-Engine.dll!UWorld::BlockTillLevelStreamingCompleted() Line 4434 C++
UnrealEditor-Engine.dll!UEngine::BlockTillLevelStreamingCompleted(UWorld * InWorld) Line 16094 C++
UnrealEditor-UnrealEd.dll!UEditorEngine::Tick(float DeltaSeconds, bool bIdleMode) Line 2153 C++
UnrealEditor-UnrealEd.dll!UUnrealEdEngine::Tick(float DeltaSeconds, bool bIdleMode) Line 551 C++
UnrealEditor.exe!FEngineLoop::Tick() Line 5906 C++
[Inline Frame] UnrealEditor.exe!EngineTick() Line 60 C++
UnrealEditor.exe!GuardedMain(const wchar_t * CmdLine) Line 187 C++
UnrealEditor.exe!LaunchWindowsStartup(HINSTANCE__ * hInInstance, HINSTANCE__ * hPrevInstance, char * __formal, int nCmdShow, const wchar_t * CmdLine) Line 267 C++
UnrealEditor.exe!WinMain(HINSTANCE__ * hInInstance, HINSTANCE__ * hPrevInstance, char * pCmdLine, int nCmdShow) Line 335 C++
[Inline Frame] UnrealEditor.exe!invoke_main() Line 102 C++
UnrealEditor.exe!__scrt_common_main_seh() Line 288 C++