UConsole HistoryBuffer no longer writing to disk in packaged builds

UE - CoreTech - Sep 7, 2023

We started running into issues with the console history not saving after upgrading to 5.2.1. The console history (as in the commands last input into the in-game console) is no longer being saved bet ...

High Virtual Texture Sample/Lookup Cost when using a Virtual Texture in a Material Layer Blend

UE - Rendering Architecture - Materials - Mar 14, 2025

Some Material Attribute blends in Material Layer Blends can cause Virtual Texture samples to be duplicated in HLSL. This can be avoided by sampling the Virtual Texture in the Parent Material, and pa ...

Lightmass GI doesn't work with Material-based color changes

UE - Graphics Features - Sep 4, 2015

A licensee is having trouble getting the visual results they want because Lightmass doesn't seem to handle color changes from materials. They are seeing this in 2 cases: (See attached images and tes ...

Particle record in the Matinee leads to crash when playing after record.

Tools - Oct 19, 2017

Particle record feature in the matinee seems not properly working in the Editor. When trying to play in the matinee with recorded keys, the Engine will crash with Access violation - code c0000005. ...

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 ...

UnrealCEFSubProcess requires Visual Studio 2013 to be compiled

UE - Foundation - Cpp Tools - UnrealBuildTool - Oct 21, 2016

When trying to build the entire engine solution or UnrealCEFSubProcess directly, Visual Studio 2013 is required to be installed for UnrealCEFSubProcess to complete successfully. There is also an err ...

Strange intermittent CCD behavior on constrained physics bodies

UE - Simulation - Physics - Oct 23, 2019

There is some strange issue with CCD where constrained CCD objects can get velocity nulled when hitting things while constrained, its very hard to reproduce normally in engine but happens often in V ...

GAS and single process PIE: modifiable static variables accessed by server and client

UE - Gameplay - Gameplay Ability System - Nov 16, 2022

See: UAbilitySystemGlobals::HandlePreLoadMap GAS features static variables that are modified by both server and client, thus result in issues in single process PIE where they access the same memory ...

When duplicating the last point in a closed-loop spline, its metadata is inserted at the wrong index

UE - Editor - Workflow Systems - Nov 1, 2023

The SplineComponentVisualizer allows users to alt+drag on a spline point to duplicate it. When this is done on the last point of a spline marked as "closed-loop", the new point is correctly added at ...

[bink video]Auto importing bk2 creates an asset with wrong path

RAD - Bink Video - May 27, 2024

Here is a work around : #include "binkplugin_ue4.h" UObject* UBinkMediaPlayerFactory::FactoryCreateBinary( UClass* Class, UObject* InParent, FName Name, EObjectFlags Flags, UObject* Context, co ...