4.25 TextRenderActor Assert on Load

Development Programming & Scripting
1

In 4.25, having textrenderactors in levels causes asserts while loading

One of the task graph threads gets this assert
FMICReentranceGuard(const UMaterialInstance* InMaterial)
{
Material = const_cast<UMaterialInstance*>(InMaterial);

	check(IsInRenderingThread() || IsInGameThread() || IsAsyncLoading() || GIsSavingPackage);

For our workaround, we deleted the text renderers in the levels

Here is the full callstack

FMICReentranceGuard::FMICReentranceGuard(const UMaterialInstance * InMaterial) Line 39
UMaterialInstance::GetMaterial() Line 657
FTextRenderSceneProxy::FTextRenderSceneProxy(UTextRenderComponent * Component) Line 660
UTextRenderComponent::CreateSceneProxy() Line 1096
UE4Editor-Renderer-Win64-Debug.dll!FScene::AddPrimitive(UPrimitiveComponent * Primitive) Line 1291
FRegisterComponentContext::Process::__l2::(int Index) Line 92
UE4Function_Private::TFunctionRefCaller(int),void __cdecl(int)>::Call(void * Obj, int & ) Line 549
ParallelForImpl::TParallelForData>::Process(int TasksToSpawn, TSharedRef>,1> & Data, bool bMaster) Line 172
ParallelForImpl::TParallelForTask>::DoTask(ENamedThreads::Type CurrentThread, const TRefCountPtr & MyCompletionGraphEvent) Line 126
TGraphTask>>::ExecuteTask(TArray> & NewTasks, ENamedThreads::Type CurrentThread) Line 849
FTaskThreadAnyThread::ProcessTasks() Line 1039
FTaskThreadAnyThread::ProcessTasksUntilQuit(int QueueIndex) Line 863
FTaskThreadBase::Run() Line 529
FTaskThreadAnyThread::Run() Line 941
FRunnableThreadWin::Run() Line 84
FRunnableThreadWin::GuardedRun() Line 27
FRunnableThreadWin::_ThreadProc(void * pThis) Line 36

Please advise:
Is this a clear bug that has a good chance of getting fixed soon?
Is there another workaround we should consider?

2

Seeing the same thing (4.25.1) when I launch a Standalone Game, or server travel to a level in a packaged build - happens if a TextRenderComponent has a material instance (rather than a material) set as its text material. I filed an issue.

For a temp fix, in FRegisterComponentContext::Process() change !FApp::ShouldUseThreadingForPerformance() to true to prevent moving this work to a worker thread seems to fix it… not sure if there will be any undesirable side effects

3

I assumed we got the answer on UDN, but it was the other way around. Thanks Eric!

4

From Epic’s response on UDN, they aren’t prioritizing supporting TextRenderActors:

Sorry for the delay, but I’m glad you got an answer that was helpful! If their solution works for you, I’ll write it down as a possible fix for these issues in the future.

A suggestion I would also add is whether utilizing a UMG widget with text boxes would better fit your needs. You can find some tutorials for them here: UMG UI Designer - How To | Unreal Engine Documentation. While widgets have a little more overhead than TextRenderActors, they are much more stable and flexible. Currently changes to TextRenderActors is considered low priority, as widgets can accomplish much of the same functionality on a more consistent basis.

Thank you for taking the time to report this issue, and let us know if either of these solutions fail to fix your problem.

5

Thanks for the info. Also found this Unreal Engine Issues and Bug Tracker (UE-42454) which sounds like the same underlying issue, it looks like a fix is targeted for 4.26.