Exception generated launching Horde Agent built with 5.6

UE - Foundation - Horde - Server - Jul 28, 2025

The source of the problem seems to be using IOptionsSnapshot with a Singleton. Per the MS documentation for IOptionsSnapshot, "Is registered as Scoped and therefore can't be injected into a Singleto ...

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 ...

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/ ...

Artifacts appear on translucent particle systems during camera motion blur

UE - Rendering Architecture - Jul 23, 2025

Translucent particle systems exhibit visual artifacts when the camera moves, even though motion vectors are disabled for the particle emitters. While switching the Translucency Pass to "After Motio ...

Custom Primitive Data color widget not applying correctly to static mesh components in Blueprint editor.

UE - Rendering Architecture - Materials - Jul 23, 2025

Context Custom Primitive Data is used to store custom data in an index array that is accessible through Blueprint and code. This allows for variations across instances of the same mesh without needi ...

The speed and delay of Animators is increased in exports when the scene contains 3D Grass

TM - Rendering - Jul 23, 2025

Reported in SF [Link Removed] For animators (translators and rotators), when the scene contains the 3D Grass materials, videos exported from the scene will display animators delay and speed up abou ...

Farfield shadow in lumen scene

UE - Graphics Features - Jul 21, 2025

Shadows in the Lumen Scene from Lumen's Direct Lighting do not match the world when in the Lumen Far Field. This leads to shadows where there should not be any, and missing shadows where there shou ...