Reimporting static mesh doesn't respect changed lightmap settings

UE - Editor - Content Pipeline - Import and Export - May 11, 2023

Licensee reports change of behaviour between UE4 and UE5 when reimporting a mesh after changing its lightmap build settings. Change of behaviour occurred in 17404767, which was to fix a similar pro ...

ULevelEditorDragDropHandler::PreviewDropObjectsAtCoordinates : Should set proper referencer domain when ContentBundle is active

UE - World Creation - Worldbuilding Tools - World Partition - Aug 21, 2023

ULevelEditorDragDropHandler::PreviewDropObjectsAtCoordinates sets the World as the ReferencingAsset when we should probably set the GameDataAsset for the current active ContentBundle if there is any ...

Material Layers "swap" location instead of shift downwards.

UE - Rendering - Architecture - Materials - Oct 17, 2023

Licensee request for this as it is affecting productivity. Likely requires a method of allowing a user to choose which behaviour they prefer. For reference, the behaviour changed in CL 11684461 to f ...

External Actors can hold stale references to Blueprint classes as edited instance properties

UE - World Creation - Worldbuilding Tools - Nov 14, 2024

When a component is removed from a class that exists as an instance with external actors enabled, a deleted BP component on an actor will remain referenced by the instance. Disabling External Actor ...

Nanite mesh not culled when owner is editor only actor in gameview

UE - Rendering - Graphics Features - Nanite - Mar 29, 2024

Nanite mesh is not culled because "DrawInGame" value in the primitive uniform buffer is always 1. Can be fixed with below modification:// in FPrimitiveSceneProxy::FPrimitiveSceneProxy DrawInGa ...

UInstancedStaticMeshComponent::AddInstances does not appear to be adding per-instance previous transforms when enabled

UE - Rendering - Graphics Features - Dec 3, 2025

Instanced static mesh component does not add instances transforms to PerInstancePrevTransform array when using UInstancedStaticMeshComponent::AddInstances. Additionally Updating the transforms of th ...

On the Details Panel of Niagara Function Inputs, the Type selector does not show "Static" types.

UE - Niagara - Apr 7, 2025

Consider a Niagara Function or Module Script containing a Static Switch node. If the "Expose as Pin" option is enabled for its selector variable, an input pin with type "static bool" appears. In one ...

Cannot Delete Event Dispatcher inside of a child blueprint when the parent has an event dispatcher as well

UE - Gameplay - Blueprint - Apr 2, 2015

If the user creates two blueprints and parents one to the other and then creates 3 event dispatchers in total between the two in an alternating method it will cause and error and the event dispatch ...

Building lighting fails on Linux

UE - Platform - Linux - Jan 15, 2016

When building lighting on Linux, the build process fails because UnrealLightmass cannot find the library libUnrealLightmass-Serialization.so. Reported using Mint Cinnamon 17.3 Internal machine uses ...

Refraction breaks Translucent Sort Order without Separate Transparency Enabled

UE - Graphics Features - Jan 6, 2016

With multiple Translucent Material sorted in 3-D space or via Transparency Sort Priority, if one of the materials uses refraction it will render on top of the others no matter position or sort prior ...