Linear interpolation occurs on constant tangent curve partially

UE - Anim - Runtime - Feb 17, 2025

When using UV scrolling for a flipbook-like animation in Animation Sequence, creating keys with "Constant Tangent" settings on Curve Editor does not result in an instantaneous change to the specifie ...

Crash when calling SetState inside state machine OnUpdate

UE - Anim - Sep 5, 2025

The crash happens when SetState is called inside the function bound to OutputAnimationPose’s OnUpdate in the animation state. This way of using Set State node is the same as shown in the official do ...

Crash when using StaticDuplicateObject with mismathced Source and Destination class types

UE - Foundation - Jun 19, 2025

Starting in Unreal Engine 5.4, StaticDuplicateObject internally switched to using Unversioned Property Serialization (UPS) for performance reasons. However, UPS assumes the source and destination ob ...

An ensure is triggered when a StaticMesh is set inside a StaticMeshComponent on an actor, and another actor references the static mesh actor from two child actor components.

UE - Framework - Blueprint - Feb 5, 2025

There is an issue when setting a Static Mesh inside a blueprint that it is referenced by another blueprint with more than one child actor. An ensure is triggered inside the engine, and there is a ...

"StaticFindFirstObject: Ambiguous object name" on delegates with timelines in packed level actors

UE - World Creation - Worldbuilding Tools - Level Instances - Jan 31, 2024

Copying a grouped MaterialInstanceParameterDetail property that has spaces on it's name does not enclose it in double quotes, and later pasting won't work as expected

UE - Rendering Architecture - Materials - Aug 24, 2025

Copying a grouped MaterialInstanceParameterDetail property that has spaces on it's name does not enclose it in double quotes, and later pasting won't work as expected. The licensee noticed this in a ...

Niagara Fluids Plugin creates a memory reference of any saved level by only being active, before being actually used.

UE - Niagara - Aug 21, 2024

While Niagara Fluids Plugin is active it creates a memory reference of any saved level regardless of being actually used. Simply enabling the plugin shows a memory reference while deleting the level ...

Crash when displaying lumencards on map with many objects

UE - Graphics Features - Lumen - Aug 1, 2025

There is a thread conflict between FRDGBuilder execution in Background Worker and LumenVisualizer's LumenCard add/delete process. When lumen cards are displayed in a scene with many objects, a crash ...

USplineComponent::FindLocationClosestToWorldLocation does not function correctly with non-uniform scale

UE - Gameplay - Components - Jul 19, 2022

Licensee reports incorrect results with FindLocationClosestToWorldLocation when used with non-uniformly scaled spline components. ...