Orphaned BP actors when using UWorldPartitionBuilder

UE - World Creation - Worldbuilding Tools - World Partition - Nov 21, 2025

From an EPS case: --------------------------------- We're seeing a recurring issue where child BP actors are becoming orphaned during any processing that uses UWorldPartitionBuilder. It affects ...

Lags in animation when set leader pose component is used

UE - Rendering Architecture - Aug 2, 2023

https://udn.unrealengine.com/s/question/0D54z00009UJv5HCAT/lags-in-animation-when-set-leader-pose-component-is-used From licensee: "USkinnedMeshComponents have the option to double-buffer their bo ...

UMG Widget color and Text color has different output at UE4 editor to Mobile preview and Mobile device.

UE - Editor - UI Systems - Jul 3, 2015

UMG Widget color and Text color has different color output at UE4 editor to Mobile preview and Mobile device. https://udn.unrealengine.com/questions/251945/umg-viewport-device%E1%84%8B%E1%85%A6%E1% ...

ARCore plugin missing 'tools' components

UE - Platform - XR - Jul 28, 2018

https://forums.unrealengine.com/development-discussion/vr-ar-development/1494917-ue-4-20p4-arcore-image-database-cannot-build/page2 Bo Pang from Google writes: "I think there are two issues here: 1 ...

RestrictedToClasses UCLASS Meta expects space delimiters but documentation shows comma delimiters

UE - Gameplay - Jul 19, 2019

The documentation: https://docs.unrealengine.com/en-US/Programming/UnrealArchitecture/Reference/Metadata/index.html shows the RestrictedToClasses meta syntax as being RestrictedToClasses="Class1, C ...

NiagaraSystem with EniagaraGpuComputeTickStage::PostInitViews rarely crashes due to multi-thread race conflicts

UE - Niagara - Mar 1, 2025

NiagaraSystem with EEiagaraGpuComputeTickStage::PostInitViews should not have bSupportsParallelGDME because of possible multi-threaded contention, but FNiagaraSystemInstanceController::GetGpuCompute ...

Mutable constant texture variable with ClipUV mask only works with new experimental dynamic variable is connected as well

UE - Anim - Mutable - Sep 22, 2025

We are attempting to use Mutable in 5.6.1 and have encountered an issue which we are not sure how to resolve. The issue occurs when using the ClipWithUVMask node. In short we have a customizable o ...

Fixup Redirectors doesn't work in the editor

Tools - Apr 28, 2015

Fixup Redirectors doesn't work in the editor when showing redirectors using the filter and then choosing Fixup. The maps that reference the redirectors aren't being checked out and fixed. I'm just g ...

OpenXR Remoting fails to attach actions to remoting session in 4.27

UE - Platform - XR - Jul 13, 2021

Regression from 4.26 where actions fail to bind when remoting in 4.27 Repro: using the Microsoft OpenXR Extensions plugin here:https://github.com/microsoft/Microsoft-OpenXR-Unreal/tree/main/MsftOpe ...

Nav Mesh Not Generating on Static Mesh Created From BSP

UE - AI - Oct 12, 2016

Nav Mesh is not being generated on a static mesh that was converted from a BSP. Found in 4.13.1. Reproduced in 4.12.5 and 4.14 Main CL 3156733 Attached is a screenshot showing the difference betw ...