Unreal Engine Issues
Unreal Engine Issues
GPU Particle Emitter noticable stutter with steady stream
UE - Graphics Features - Apr 1, 2016When using a GPU particle and setting a steady stream there is an obvious stutter compared to 4.10.4 where everything worked smoothly. Regression: YES This issue did not occur in 4.10.4 CL-2872498 ...
Landscape Visibility Mask Rendering with Missing Landscape Components when Deployed to Mobile Device
UE - Graphics Features - Apr 8, 2015Landscape Material renders with missing components when using a 'Landscape Visibility Mask' and deploying to a mobile device. I have found this issue now with an Android and iOS device. I was able ...
Behavior Tree Decorator Not Aborting When Observer Aborts is Set in Behavior Tree
UE - AI - Jun 15, 2016Behavior Tree Decorators are not aborting when observer aborts is set in the Behavior Tree. Setting Observer Aborts inside of the Decorator blueprint causes it to work as expected. Found in 4.12.2. ...
Cannot Compile GitHub Source Code for UE4 Game on Mac
UE - Platform - Apple - Apr 16, 2015Dowloaded 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 - Core - Systems - Mar 18, 2026FJsonObjectConverter::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, 2016The 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, 2016When 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, 2016When 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, 2017A 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 - Runtime - Simulation - May 21, 2026A 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 ...