Importing FBX that contains a socket from Blender to Unreal, the socket gets rotated by 90° and is scaled by 100

UE - Editor - Content Pipeline - Import and Export - Sep 9, 2025

Context: Sockets are attach points that can be placed on a Static Mesh to attach an object to the static mesh. Problem: Importing an FBX that contains a socket from Blender to Unreal, the socket ge ...

Calling a child's child in a child blueprint from a spawn actor from class node that is being called back to the child causes an error

UE - Gameplay - Blueprint - Jun 29, 2015

Calling a child's child in a child blueprint from a spawn actor from class node that is being called back to the child causes an error. Basically, when using the spawn actor node referencing the chi ...

ARCore Non-AR Camera inherits AR Camera rotation

UE - Platform - XR - Jul 25, 2018

When transitioning from AR map/pawn to Non-AR map/pawn the direction the phone is facing is applied to Non-AR pawn. Only occurring on Android/ARCore Also tested in Main CL #4229747 Tested with Pi ...

Hot Reload fails if a project and Engine are placed next to each other in the same root folder that has the same name as the project

UE - Foundation - Cpp Tools - Hot Reload - Jan 8, 2019

Hot Reload does not work if a project and the Engine that project is associated with are placed next to each other in the same root folder that shares the same name as the project. During the Hot Re ...

Previous Tangent Recalc` and Size by Life misbehave at low FPS

UE - Niagara - Jun 18, 2019

At low FPS particle systems with "Previous Tangent Recalculation" enabled in the Ribbon Data result in messy mesh generation. Found in 4.21 CL# 4753647, 4.22 CL# 6574378, 4.23 CL# 6925347, and 4.24 ...

Skybox not rendering in packaged project with Vertex Fogging enabled

UE - Platform - XR - Feb 10, 2020

Vertex Fogging setting causes skybox material on large skybox mesh to not be rendered. Confirmation for 4.25 blocked by [Link Removed] ...

Actor attached to child actor fails to serialize as part of map

UE - Framework - Components - Nov 3, 2023

Attaching other actors to a child actor (actor spawned by ChildActorComponent) fails to serialize correctly as part of the map. The attached actor loads as detached and resets its position back to w ...

UV Offset Effect Material in RetainerBox Causes Visual Artifacts in Editor Preview

UE - Editor - UI Systems - UMG - Apr 22, 2025

When a UV Offset is applied in a RetainerBox effect material, visual artifacts appear only in the editor — not at runtime — if a widget with a dotted preview outline (like CanvasPanel) is placed dir ...

20 FPS performance drop between 4.7.6 and 4.8 on devices rendering Metal only

UE - Platform - Mobile - Jun 22, 2015

User reported a considerable performance drop on iOS between versions 4.7.6 and 4.8. I was able to reproduce this perf drop using the steps he provided. ...

BP child not overriding parent's mesh in Nativized builds

UE - Gameplay - Blueprint Runtime - Jan 3, 2017

The mesh on the right is a child of the one on the left, in a non-nativized cooked build it's a sphere, but in a nativized one, it's a cube. Regression: Working: UE4/Main, 4.15 CL 3233043 Broken: U ...