Child Actor Component Actor Duplicates and Persists After Play

UE - Gameplay - Sep 26, 2019

When an actor spawns another actor using AddChildActorComponent that comes alphabetically before it based on blueprint name it will spawn an extra actor that will persist when the scene is stopped d ...

With Ray Tracing Enabled And The RenderDoc Plugin Enabled Shadows Don't Render Correctly On Reflective Materials

UE - Graphics Features - Lumen - Jan 23, 2020

When the RenderDoc plugin is installed with raytracing enabled shadows don't render correctly. Found in 4.24.1 CL#10757647 Reproduced in 4.23.1 CL#9631420, 4.25 Main CL#11087956 ...

[Soundfield Submix][Crash] - Unreal Ambisonics Crashes on Packaged Game and in Standalone

UE - Audio - Submixes - Jan 11, 2021

Issue was reported by a user on the Unreal Engine forms. I tried to package the game with the other encoding options and this appears specific to using the Unreal Ambisonics option.  I have only co ...

Motion vectors not generating correctly in build

UE - Simulation - Physics - Nov 3, 2023

Also tried using “show VisualizeTemporalUpscaler” and noticed the frames that have missing motion vector data showed up as pops in the “show VisualizeReprojection” part of the visualizer. ...

Bitfield enums don't cast correctly in Blueprints

UE - Gameplay - Blueprint Compiler - Jan 22, 2025

The licensee already investigated this a little. The problem appears to be that UKismetNodeHelperLibrary::GetValidValue should be calling IsValidEnumValueOrBitfield as opposed to IsValidEnumValue. ...

When importing static mesh using interchange and collision is generated, the asset does not have Collision Generated set to true

UE - Editor - Content Pipeline - Import and Export - May 19, 2025

Context: The Interchange Framework is Unreal Engine's import and export framework. When importing a mesh without collision, collision can be auto-generated. Problem: The problem is when importing s ...

Water tiles flicker in and out of visibility with instanced stereo enabled.

UE - Graphics Features - Jun 16, 2025

Water tiles flicker in and out of visibility when playing in VR with instanced stereo enabled. Requires instanced stereo rendering to be enabled (does not require forward shading to be enabled) Must ...

Lumen reflections break when the normals don't match the pixel depth information.

UE - Graphics Features - Lumen - Oct 23, 2025

Lumen Reflections can leave black spots in chrome materials with strong normals. Also tested on UE 5.5, CL: 41545209 and UE 5.6, CL: 45232827 ...

Control Rig - Undo doesn't function correctly with proxy and multi bone controls

UE - Anim - Rigging - Control Rig - Oct 26, 2025

Issue from my Technical Animator where the undo operation in Control Rig doesn't work as expected on Proxy Controls. He has recreated the issue using the "Control Rig Samples Pack" and recorded a vi ...

Adding to Struct causes 'Inappropriate Outermost' warnings

UE - Gameplay - Blueprint - Jun 2, 2015

Adding to Struct causes 'Inappropriate Outermost' warnings to be spammed to the Output Log ...