Unreal Engine Issues
Unreal Engine Issues
Lightmass: Blocky lightmap artifacts appears on the Mesh Actor which is shadowing by a single face mesh
UE - Graphics Features - Lumen - Jun 9, 2020Begin Map Begin Level Begin Actor Class=/Script/Engine.StaticMeshActor Name=Plane_2 Archetype=/Script/Engine.StaticMeshActor'/Script/Engine.Default__StaticMeshActor' Begin Object Class=/Script/En ...
[CrashReport] UE4Editor_Engine!LoadSpecialMaterial() [unrealengine.cpp:1523]
UE - Graphics Features - Nov 10, 2017This is a longstanding crash that has occurred for more than 200 users since at least 4.13. Based on user descriptions this appears to permanently corrupt a project. User DescriptionsI just turned ...
SceneCulling: MarkCellBoundsDirty overwrites dirty flags, leaving static chunk explicit bounds stale when a cell gets static and dynamic marks in the same frame
UE - Rendering - Architecture - Oct 14, 2026Summary FSceneCullingMarkCellBoundsDirty(CellIndex, bStaticChanged, bDynamicChanged) (Engine/Source/Runtime/Renderer/Private/SceneCulling/SceneCulling.cpp, ~line 1907) assigns DirtyCellBoundsMaskStat ...
The Geometry Collection Dataflow node CreateGeometryCollectionFromSources is breaking Material Assignment
UE - Runtime - Deformable - Jul 21, 2025The Geometry Collection Dataflow node CreateGeometryCollectionFromSources is breaking Material Assignment. As the licensee has pointed out, this previously worked in 5.5. The most probably cause fo ...
[CrashReport] UE4Editor_CoreUObject!UObjectPropertyBase::Identical() [propertybaseobject.cpp:60]
UE - Foundation - Cpp Tools - Hot Reload - Nov 17, 2016This Jira was created from CrashReports submitted by the public due to the high number of occurrences. Error message: Access violation - code c0000005 (first/second chance not available) Source C ...
User-defined InstancedStaticMeshComponent subclass misbehave in SCS Editor
UE - Framework - Blueprint Editor - Oct 13, 2025Context Users can create InstancedStaticMeshComponent (ISMC) (blueprint) subclasses. Any ISMC class can be added to an actor blueprint. When a mesh is selected and transforms are added to the Insta ...
Crash when a subsystem calls GetSubsystemArray() on its owner while engine code is iterating on subsystems also obtained through GetSubsystemArray()
UE - Gameplay - Aug 6, 2024In some occasions, engine code iterates over a certain subsystem type by calling FSubsystemCollection::GetSubsystemArray() and then calling some method on all subsystems of the returned array. This ...
Sequencer : Attaching a Possessable to multiple Spawnables across multiple cuts causes incorrect location restoration
zComponent - Archive - Nov 12, 2021Regression No, according to affects versions 4.27 and 4.27.1 The restore process proceeds in the following order : 1. Remove spawnable actor in first cut (no effect because the actor is already r ...
"FVector contains NaN" on packaged builds for Debug configuration
UE - Rendering - Features - Lumen - May 6, 2022Customer Provided Description:This was experienced in UE 5.01 - custom installed engine (No changes to UE code, simply added the Debug build configuration, see the following command): "c:%ue_dire ...
GAS: GameplayCueNotify OnActive executed twice for Duration GEs on Standalone+ListenServer
UE - Gameplay - Gameplay Ability System - Aug 2, 2023When playing Standalone or as Listen Server, whenever a GameplayEffect with a duration is applied that fires gameplay cues, the server will locally execute OnActive twice on GameplayCueNotify_Actors ...