[Groom] Very thin hair has incorrect raytraced shadow on edges

UE - Graphics Features - Lumen - Jun 8, 2020

This only happens when 1) Hair Width is very small. e.g. 0.01 in the example 2) Light has raytraced shadow and Samples Per Pixel has a value > 1. e.g. 8 in the example The problem seems to be rel ...

Key input by Sequencer is missing in FBX output of parent-child actors

UE - Anim - Sequencer - Nov 15, 2021

This problem did not occur in 4.27.0. Animation is not output when outputting a hierarchical structure. Actor(A)   ┗Actor(B)     ┗Actor(C) This is how the attachments are registered, and the ke ...

Actors in Level Sequence in a World Partitioned level do not move

UE - World Creation - Worldbuilding Tools - World Partition - Jan 11, 2023

Regression: Tested in UE5/Release-5.0, this issue does not occur so it is a regression This issue occurs when the cube has "Is Spatially Loaded" enabled in Details as well as when the cube is added ...

Adjusting transform of a mesh with LODs causes LODs to flicker

UE - World Creation - Worldbuilding Tools - Foliage - Jun 3, 2015

If a hierarchical instanced static mesh has LODs and is scaled in a blueprint, the mesh will rapidly switch between LODs, causing a flickering effect. Note: This only seems to occur if the camera ...

Incorrect display for default exec pin for Switch nodes

UE - Gameplay - Blueprint Editor - May 4, 2017

The pin for Default for switch nodes in the preview build for 4.16 displays as a circle, this visual display for a pin is used with variables or a reroute node, but the default is and exec pin, and ...

FHLSLMaterialTranslator::GetMaterialEnvironment can crash or not load UMaterialParameterCollections

UE - Rendering Architecture - Materials - Apr 30, 2025

In UE 5.5, the Editor may crash in FHLSLMaterialTranslator::GetMaterialEnvironment when loading materials with Material Parameter Collections, likely due to async loading. Calling ParameterCollectio ...

HTML5 fails during Package Command with ASM enabled

UE - Platform - Mobile - May 10, 2017

While testing in //UE4/Release-4.16 CL 3432136 in Binary – Launching a blueprint - FirstPerson template to Chrome encounters an error.LogPlayLevel: Program.Main: ERROR: AutomationTool terminated wit ...

UBT warning during package when nativized blueprint contains a node from a plugin

UE - Gameplay - Oct 9, 2017

When a Blueprint contains a node that was added by a plugin (ex: GetBatteryLevel node added by Optional Mobile Features Blueprint Library), nativizing the BP in 4.16 completed fine but 4.17 gives a ...

GoogleARCoreJavaHelper functions are not correctly exported publicly

UE - Platform - XR - Oct 31, 2018

The jni functions in GoogleARCoreAndroidHelper.cpp are not correctly exported, when we tried to build a Test project it failed with this exception:  java.lang.UnsatisfiedLinkError: No implementatio ...

Crash: Landscape Materials Missing on Shipping and Development Packaged Builds

UE - Foundation - Core - Sep 9, 2019

When running a packaged build of a project with a level with a landscape that has a material assigned it will crash (shipping build) or not retain the assigned material (development build). There i ...