Unreal Engine Issues
Unreal Engine Issues
Skeletal mesh LODs never stream up under SSAM: FSkeletalMeshSceneProxy caches ForceStreamedLOD and is never re-gathered
UE - World Creation - Worldbuilding Tools - Jul 29, 2026UE 5.8, cooked build, SSAM enabled (s.StreamableAssets.UseSimpleStreamableAssetManager=1, required by FastGeo). Symptom: characters spawn at a crude LOD and can never stream up for the lifetime of ...
StreamingGeneration: Actor desc mutator phase now writes ActorDescView directly, breaking the cluster-invariant check in ValidateContainerInstanceDescriptors
UE - Engine Scaling - Streaming - World Partition - May 22, 2026This report is from an EPS case: We hit a regression upgrading our project from 5.7 to 5.8. Map Check (and any other path that ends up calling UWorldPartition::CheckForErrors) assert inside FWorld ...
FGameplayTagCountContainer::Reset() leaves explicit tag state and causes counts to accumulate
UE - Gameplay - Gameplay Tags - Aug 4, 2026[Summary] In UE 5.7 and later, if a tag is added once to an FGameplayTagCountContainer, the container is reset, and the same tag is added once more, GetExplicitTagCount() returns 2 instead of the e ...
Crash when a StateTree-related Parameter is of a type that includes two nested arrays with the same name (due to FPropertyChangedEvent::ArrayIndicesPerObject using array names to map to their changed indices)
UE - Framework - Dec 19, 2025This issue was reported in the context of adding and setting parameters on StateTrees, Tasks and related assets, but its root cause lies in the structure FPropertyChangedEvent and can possibly affec ...
When ParallelExecutor is enabled, Japanese build output of VisualStudio garbled
UE - Foundation - Cpp Tools - Sep 19, 2018From UE4.20, Japanese build output of VisualStudio garbled. Below is a comparison between 4.19 and 4.20. ・4.19.2 1>------ すべてのリビルド開始: プロジェクト:MyProject3, 構成:Development_Editor x64 ------ 1> Clea ...
Crash on FDeferredShadingSceneRenderer & FTranslucentPrimSet with Dynamic Directional and Lit Translucent FX
UE - Graphics Features - Nov 11, 2015User reporting crash with a specific setup using Lit Translucent FX Clouds and a Day-Night Setup running on a Timeline from Level Blueprint. [Link Removed] 4.8 BUGG: [Link Removed] 4.9 BUGG: [Li ...
[CRASH]SIGSEGV: invalid attempt to access memory at address 0x0
Tools - Jan 7, 2015Callstack: <CALLSTACK START> FTaskThread::ProcessTasksUntilQuit(int) Address = 0x1091943e5 (filename not found) [in UE4Editor-Core.dylib] RenderingThreadMain(FEvent*) Address = 0x10de37e4b (filena ...
Constant Crashes on OS X 10.10.1
UE - Platform - Apple - Dec 15, 2014User (Omri) on Mac running OS X 10.10.1. on MacBook Pro (17-inch, Early 2009 Experiencing Crash. Cannot reproduce. Crash Reporter: N/A Callstack: MachineId:1E07B9CE2F4554A7C3F421A9DD97AFB5 EpicAc ...
[Feature Request] CVars for HISMC
UE - World Creation - Worldbuilding Tools - Foliage - Jun 18, 2021Currently some (if not all or most) foliage CVars affect both foliage and HISMC. It would be nice to split this so that users can change the values of one without affecting the other. ...
DestructibleMesh does not correctly effect vertex color of material.
UE - Simulation - Physics - Destruction - Oct 10, 2017Destructible Mesh does not correctly affect vertex color. ...