NormalizePackageNames() should interpret 'exclude developer folders' to also exclude packages in ExternalActors and ExternalObjects

UE - CoreTech - Oct 14, 2022

In NormalizePackageNames() (PackageUtilities.cpp), there is a PackageFilter parameter, which can be set to exclude developer packages (NORMALIZE_ExcludeDeveloperPackages). The code only checks the b ...

Placing a section at the end of montage is not properly handled

UE - Anim - Gameplay - Feb 24, 2024

Placing a  section at the very end of a montage with no duration or animation assigned after it is not properly handled.  Normally sections with 0 length are skipped and search continues since they ...

FAnimMontageInstance::SetNextPositionWithEvents can trigger all notifies on a montage/sequence

UE - Anim - Runtime - Jun 24, 2025

This issue happens when Sequencer loops a dynamic montage. FAnimMontageInstance::ForcedNextFromPosition is set to 0 and ForcedNextToPosition is effectively the delta time. However, FMontageSubStep ...

Landscape Textures Patches issue when using "Texture Backed Render Target" as the Height Patch Source Mode where Landscape patches are not applying properly the first time a level is opened after restart

UE - Graphics Tools - Terrain - Landscape - Oct 6, 2025

Context: Landscape patches are components that can be attached to meshes to affect the landscape as the mesh is repositioned. Problem: The problem is that when using "Texture Backed Render Target" ...

World Partition Editor minimap build failed

UE - World Creation - Worldbuilding Tools - Aug 10, 2023

The issue was reproduced when building a minimap for an open world level with no Actors with "Is Spatially Loaded" enabled. Placing additional Actors with "Is Spatially Loaded" enabled in the level ...

Lumen ignores Landscape Holes (Landscape Visibility) when Hardware Ray Tracing is enabled and Ray Lighting Mode is set to Surface Cache

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

Context Lumen is the default global illumination and reflections system. Lumen renders diffuse interreflection with infinite bounces and indirect specular reflections in large, detailed environments ...

Switching modular control rig to FK mode breaks pose of controls that have been baked to rig

UE - Anim - Rigging - Control Rig - Sep 14, 2025

From the licensee:We have built a modular Control Rig in Unreal 5.6, and while IK to FK matching works correctly inthe rig, but we are facing an issue when applying mocap animation to the characters ...

Crash when calling FillDataTableFromCSVString() while viewing the contents of the data table

When the function UDataTableFunctionLibrary::FillDataTableFromCSVString() is used from Editor Utility Blueprints or Python Scripts, and the contents of the affected Data Table are currently being vi ...

Sequencer - When a subsection has negative play rate, any nested sub-subsections fail to evaluate

UE - Anim - Sequencer - Jul 3, 2025

Consider a sequence hierarchy with more than two layers. If the top-level sequence uses a negative timescale on a sub-sequence, the contents inside it animate as expected, but any nested sub-sequenc ...

Default subobject of dynamic component skips initial replication

UE - Networking - Sep 11, 2024

Because the component's subobjects are replicated before the component, the content block for the subobject is received before the component has been created on the client. Since this subobject is c ...