Light Complexity view mode crashes if there are hair cards in the scene

UE - Graphics Features - Jul 24, 2024

The Editor will crash if Groom Hair Cards are viewed with the Light Complexity View Mode. ...

FSkeletalMeshComponentInstanceData subclasses FSceneComponentInstanceData instead of FPrimitiveComponentInstanceData

UE - Runtime - Deformable - Mar 19, 2025

FSkeletalMeshComponentInstanceData subclasses FSceneComponentInstanceData instead of FPrimitiveComponentInstanceData. When calling ApplyToComponent() the SceneComponentInstanceData version will be c ...

Collision Drawing in Cooked Builds (Development) doesn't Show Geometry for Nanite Meshes

UE - Rendering - Features - Jun 2, 2025

Context The showFlag.CollisionVisibility 1 cvar is a viewport visualization mode that highlights which Actors will block visibility. The showFlag.CollisionPawn 1 cvar is a Player Collision viewmode ...

FInstancedStruct does not serialise to JSON when used in a DataTable

UE - AI - Aug 4, 2025

The JSON export functionality for DataTable relies on a FieldIterator to gather properties. This iterator is unable to gather the properties from the InstancedStruct. CSV export functionality works ...

Landscape overdraw bug

UE - Graphics Tools - Terrain - Feb 26, 2026

When Landscape GPU Culling is operational, patches of Landscape will have heavy overdraw. This requires Nanite and Lumen to be disabled - the test project is set up with this by default. This quad ...

Potential wrong branch condition about DFAO and Niagara GPU SDF Collision

UE - Niagara - Mar 6, 2026

Particles using Distance Field collision can have their collision controlled by "r.DistanceFieldAO". It appears that the condition in "ShouldPrepareGlobalDistanceField(...)" from DistanceFieldAmbie ...

UAbilityTask_SpawnActor::BeginSpawningActor may return true when SpawnedActor contains stale value

UE - Gameplay - Gameplay Ability System - Mar 15, 2026

UAbilityTask_SpawnActor::BeginSpawningActor assumes the incoming AActor*& SpawnedActor parameter is nullptr if no actor was spawned, but it does not initialize the parameter at the start of the func ...

Projects saved outside of default folder do not show up in Project Browser on Linux

UE - Platform - Linux - Jun 17, 2015

If a project is saved outside the default Unreal Projects folder or the project folder is moved from Unreal Projects to another location it does not show up in the list of projects on the Project Br ...

Include Render Pass name as variable in Filename Format field

UE - Anim - Sequencer - Jan 4, 2016

When outputting with Custom Render Passes, the Render Pass is automatically added at the end of the output frame file name. We have a few variables that we can control in the FileName Format sectio ...

Crash in Retarget Manager with Humanoid Rig when trying to re-assign a bone to a node

OLD - Anim - May 26, 2015

Crash in the Retarget Manager with Humanoid Rig when trying to re-assign a bone to a node. Happens particularly when there is already a bone selected and you want to select a new one. [Link Remove ...