Copy-pasting custom property nodes (ControRig etc.) results in invalid bindings, perf issues

UE - Anim - Rigging - Control Rig - Jul 28, 2025

From this UDN: [Link Removed] Suggested fix:Override PostPasteNode to perform the GUID update andAdd validation on load to strip 'invalid' copies that do not correspond to a valid pin input ...

Restoring AnimInstance fails when ControlRig and Motion tracks are consecutive in sequencer

UE - Anim - Anim in Engine - Jul 27, 2025

In the Sequencer, Control Rig and Animation tracks are placed consecutively. During the transition, the Animation track captures the AnimInstance state before the ControlRig track's RestoreState is ...

Merge Actor - Approximate Actors algorithm is using Mesh Description directly rather than the Nanite parameters

UE - World Creation - Worldbuilding Tools - Merge Actor - Jul 25, 2025

In an ideal world, all mesh merge algorithms should have the option to use as input one of the followingRender mesh (non-nanite) (+ the option to target a specific LOD)Mesh Description (+ the option ...

SynchronizeWithExternalDependencies can cause soft lock with Pose Search DDC tasks during cook

UE - Anim - Gameplay - Jul 25, 2025

SynchronizeWithExternalDependencies will call Modify on the Pose Search Database when the database has changed. This will call FAsyncPoseSearchDatabasesManagement::OnObjectModified which in turn ma ...

UPoseSearchDatabase::SynchronizeWithExternalDependencies re-adds existing DB assets that don't have branch in notifies

UE - Anim - Gameplay - Jul 25, 2025

If we have PSDs that contain assets that were added manually to the database and also others that were added via branch in notifies then SynchronizeWithExternalDependencies will remove and re-add th ...

VALIDATE_UNIFORM_BUFFER_LIFETIME fails compilation

UE - Graphics Features - Jul 24, 2025

Also verified on Release-5.5.4 CL 40574608 ...

UWorldPartitionSubsystem::IsStreamingCompleted returning the wrong query result when all cells and actors in location are in DataLayers

UE - World Creation - Worldbuilding Tools - World Partition - Jul 24, 2025

Context: Data Layers is a system within World Partition used to organize Actors both in the Editor and at runtime. It allows for the user to dynamically load and unload layers in the Editor to help ...

Nanite Landscapes in Non world partition maps has missing sections

UE - Graphics Tools - Terrain - Landscape - Jul 23, 2025

Nanite in non world partition worlds builds with missing section, almost half the landscape is missing. Looking at the nanite overdraw as attached, it shows an interesting pattern. ...

ULevelSequence trying to duplicate a REINST_ class when creating new custom binding in ConvertOldSpawnables()

UE - Framework - Blueprint Compiler - Jul 23, 2025

The assert that we're hitting is:Cannot replace existing object of a different class.  New Object: /Engine/Transient.REINST_BPC_NPC_VFX_C_230 /Game/Maps/[REDACTED]/Levels/[REDACTED]/LevelSequence/ ...

heterogeneous volumes SkyLight VolScatter Intensity not working

UE - Niagara - Rendering - Jul 23, 2025

Heterogeneous Volumes do not respect the Volumetric Scattering Intensity values when running with Lumen, but do (correctly) when rendering with the Path Tracer. ...