Cannot Compile GitHub Source Code for UE4 Game on Mac

UE - Platform - Apple - Apr 16, 2015

Dowloaded 4.7.5 release from GitHub and was able to compile the UE4 Editor source code successfully. Then attempted to compile using the "UE4 - Game -Mac" filepath, but received message saying could ...

JsonObjectToUStruct removes _ClassName from input FJsonObject, breaking repeated deserialization

UE - Foundation - Mar 18, 2026

FJsonObjectConverter::JsonObjectToUStruct removes _ClassName from nested JSON objects during deserialization. Removing Obj->RemoveField(ObjectClassNameKey) from ConvertScalarJsonValueToFPropertyWit ...

Roughness rendering differently on Macs

UE - Graphics Features - Oct 4, 2016

The roughness value for Macs renders differently (less rough or glossy) compared to Windows. It also seems to render as expected within the Material Editor preview window, but when applied to an obj ...

Using the CVar `Shot` causes artifacts in the screenshot with GearVR

UE - Platform - XR - Mar 7, 2016

When using the CVar for `Shot` the produced image saved in the screenshots folder of the project on the device will has artifacts that are not the image taken. This happens when using a Gear VR Proj ...

Crash when using Landscape when building lighting with commandlet

UE - Graphics Features - Jun 6, 2016

When using the new Rebuild Lighting commandlet will cause a crash with any level that builds when it has a landscape in the scene. https://github.com/EpicGames/UnrealEngine/commit/f89256dd0efb7d0b ...

Particle Cutout Will Clip Texture On Certain Frames Even With Alpha Threshold of 0.0001

UE - Niagara - Feb 17, 2017

A licensee has reported that the particle cutout feature will sometimes clip the image on some frames despite having an alpha threshold of 0.0001 The attached project has an example of this on the ...

Non-determinism in StaticMeshComponent::BodyInstance when cooking LevelInstances

UE - Simulation - Core - May 21, 2026

A licensee reported that serialization of LevelSequence with StaticMeshActor with default collision for which mesh has NoCollision profile is not deterministic. The issue seems to be in the fact tha ...

[Console Commands] - au.debug.sounds.sort priority shows all sounds as priority 1.0 when volume scaling is bypassed or sound is 2D

UE - Audio - Apr 5, 2022

The priority display does not correctly reflect the set priorities of sounds when they are not being attenuated or when Bypass Volume Scale for Priority is Enabled. If a sound is attenuated and scal ...

Copy/pasting a Custom Event that has input names containing spaces will create a Custom Event with extra inputs

UE - Gameplay - Blueprint - Feb 4, 2015

Copy/pasting a Custom Event that has input names containing spaces will create a Custom Event with extra inputs. It appears that an input name with a space in it will be copied as two inputs, the fi ...

Behavior of configuration file hierarchy is different from document

UE - Foundation - Core - Nov 6, 2015

Licensee reported behavior of configuration file hierarchy is different form document here (https://docs.unrealengine.com/latest/INT/Programming/Basics/ConfigurationFiles/index.html) Doc: 1. Engine ...