Foot Placement: Checks should be ensures

UE - Anim - Gameplay - Feb 5, 2025

As per the title, a cosmetic anim node should not be crashing an entire game. At worst these should be ensures. Its experimental, but its important they're removed before the experimental flag is re ...

Static Meshes that are reimported with less materials can lead to map check errors on instances that had overriden materials that require manual cleanup

UE - Rendering - Architecture - Feb 5, 2025

StaticMeshActors placed in the world can override the default materials of a static mesh. If the static mesh is then reimported with less materials, the actors maintain references to unused material ...

Spline mesh crashing in FRayTracingDynamicGeometryCollection::AddDynamicMeshBatchForGeometryUpdate

UE - Rendering - Graphics Features - Ray Tracing - Jan 31, 2025

A crash occurs when using ray tracing with spline meshes preceded by the following ensure : Ensure condition failed: NumCPUVertices <= VertexBufferNumElements  File: Engine\Source\Runtime\Renderer\ ...

Replicating a non-root component with simulate physics enabled causes the component to be in the wrong place on spawn, on clients.

UE - Simulation - Gameplay - Jan 20, 2025

When a BP spawns another, if the spawned Actor has a non-root child component that is simulating physics, on clients, immediately after spawn, the child component will have the world position double ...

SetActorLabel() is slow on Landscapes

UE - Graphics Tools - Terrain - Landscape - Jan 7, 2025

I've noticed calling SetActorLabel() on a Landscape will call PostEditPropertyChanged() which causes the Landscape Components to regenerate all collisions. As per the repro, this can take a long tim ...

Inconsistent events triggered by FlushProcessedKeys during keyboard hold input

UE - Gameplay - Input - Dec 20, 2024

Key repeats from the OS do not affect the EnhancedInput normally, but it causes inconsistent event triggers when FlushProcessedKeys is called with holding a keyboard key down. Removing references t ...

Linked graphs that are linked via post process anim bp BeginPlay can be lost on reinitialization of anim instance

UE - Anim - Runtime - Anim Blueprints - Dec 16, 2024

Certain codepaths in USkeletalMeshComponent::InitializeAnimScriptInstance can cause linked anim graphs that are running in Post Process anim bps to be unlinked.  The problem only occurs when the lin ...

Issue with PLA Editing inside another PLA causes Z-Fighting or Mesh Disappearance.

UE - World Creation - Worldbuilding Tools - Dec 6, 2024

When editing a Packed Level Actor (PLA) that is inside another PLA, z-fighting or mesh disappearance will occur. More specifically, it is seen when duplicating a mesh inside the PLA, upon saving the P ...

Editor Crash When Using FRequestPlaySessionParams GlobalMapOverride To Load World Partition Map

UE - World Creation - Worldbuilding Tools - Data Layers - Dec 6, 2024

The licensee has been using a custom CVAR to launch directly into PIE for a world partition level. Since updating to 5.4, this now causes an editor crash. The main factor appears to be whether or no ...