Editor vs Runtime: Inconsistent data layer behavior when attaching actors

UE - World Creation - Worldbuilding Tools - World Partition - Jun 5, 2025

In editor, data layer system respects the data layer settings for each actor, but at runtime, the condition check is made collectively for each actor cluster, resulting in differences in behavior. ...

Editor crashes when using PCG SpawnActor with a DataLayer inside a Level Instance

UE - World Creation - Procedural Tools - Jun 4, 2025

A PCG actor is assigned to a DataLayer and placed inside a Level Instance. Then that Level Instance is placed into a World Partition map. When the SpawnActor node in the PCG graph is set to MergePCG ...

ChordBlockers don't work as expected when ChordAction is set in InputAction

UE - Gameplay - Input - Jun 3, 2025

In the Enhanced Input System, when using a UInputTriggerChordAction to define a chorded input (e.g., Shift + W), the automatic chord blocking system (UInputTriggerChordBlocker) only functions correc ...

Local lights appear broken when baking lighting with GPU Lightmass

UE - Graphics Features - Jun 2, 2025

Encountered an issue where local lights appear to be broken when baking lighting with GPU Lightmass. See screenshots attached. Tested regression in //UE5/Release-5.5 @ CL40574608 and the issue does ...

Virtual Bone caused nanite skinned mesh crash

UE - Graphics Features - Nanite - May 31, 2025

When a Nanite skeletal mesh has a virtual bone the engine can crash when changing LODs ...

Multiple setter functions in UMaterialEditingLibrary always return false even when the parameter is correctly set on the MaterialInstance.

UE - Rendering Architecture - Materials - May 30, 2025

In Unreal Engine, materials can expose parameters that can then be modified via instances (MaterialInstanceConstant). The UMaterialEditingLibrary provides several functions to modify these parameter ...

GPU Lightmass no longer works with cascaded shadow maps

UE - Graphics Features - May 29, 2025

Since Unreal Engine 5.5 stationary lights have stopped working with GPU Lightmass when using Cascaded Shadow Maps. With Virtual Shadow Maps enabled on the project, GPU Lightmass works. This issue d ...

VSM SMRT SamplesPerRay CVars behave differently if groom assets are present leading to a potential full-scene shadow

UE - Graphics Features - May 28, 2025

When a groom is present, setting any SamplesPerRay SMRT CVar to zero results in an unexpected complete shadow projected from the light. ProjectLight() in VirtualShadowMapProjection.usf has addition ...

Keyboard Shortcuts don't work on the Outliner Window if it is detached from the Main Window

UE - Editor - Workflow Systems - May 27, 2025

Keyboard Shortcuts don't work on the Outliner Window if it is detached from the Main Window. As described in Steps To Reproduce, as soon as the Outliner Window is detached from the Main Window, most ...

UAnimSingleNodeInstance doesn't sample notifies on montage animation tracks

UE - Anim - Gameplay - May 27, 2025

Notifies that are placed on animations referenced by montages aren't triggered when using the UAnimSingleNodeInstance to play back the montage. This is because - unlike on UAnimComposite - there is ...