The AABBTree spatial acceleration structure goes off-sync when physics substepping is enabled in a "low" framerate environment.

UE - Simulation - Physics - Mar 15, 2024

When you enable the physics substepping, if you run the console command p.Chaos.Solver.DebugDrawSpatialAccelerationStructure 1, you can see how does not follow the physical object. The user that rep ...

Consolidate tool fails to replace unloaded references to Material Instances

Tools - Feb 20, 2018

This issue is not a regression, it has been broken since the start of UE4. This bug may be related to [Link Removed] . Per licensee: We are trying to replace certain materials with material instan ...

Clear Coat looks incorrect in the Preview when Energy Conservation on Material is enabled for non Substrate rendering

UE - Rendering Architecture - Materials - Apr 11, 2024

Enabling Energy Conservation on Material makes Clear Coat Material look weird in Preview. It looks fine in the Level Editor, but not in any "Preview" type viewport (Material Editor, Asset Thumbnails ...

Foliage lightmaps for LODs does not look correct

UE - World Creation - Worldbuilding Tools - Foliage - Jun 21, 2016

When using the foliage tool with any mesh that has a LOD the lightmap generates artifacts for the instance. The base LOD will have correct looking lightmaps, however when pulling back and seeing the ...

[CrashReport] UE4Editor_Engine!UMaterialExpression::GetOutputType() [materialexpressions.cpp:859]

UE - Rendering Architecture - Materials - Nov 21, 2017

This is an infrequent crash in the 4.18 release. Users have not provided any descriptions of their actions when the crash occurred. Source Context 849 uint32 UMaterialExpression::GetOutputT ...

Sequencer autosorts alphabetically on undo

UE - Anim - Sequencer - Sep 8, 2023

[Link Removed] Jan Kaluza 2023-09-08 15:37:18 UTC I just ran into a very frustrating bug: I have around 60 actors in a sequence, and I reordered them to be in the order that I wanted to animate them ...

Stationary light shadow are occluded for additional players in split-screen mode

UE - Graphics Features - Jun 17, 2015

When using split screen multiplayer the second or more players that are added for split screen will have their characters shadows occluded when the bounds are not within view of player 1. Setting ...

AbilitySystemComponent::NotifyAbilityEnded Can Crash due to Callbacks Invalidation Specs

UE - Gameplay - Gameplay Ability System - Oct 11, 2023

Pasting from the UDN: Unsafe code in AbilitySystem can lead to crash when granting an ability inside OnAbilityEnded Hello. We just ran into a crash. After investigation, it seems to be caused by ...

Landscape renders default material if apply another material instance under ES31 preview

UE - LD & Modeling - Terrain - Landscape - Aug 27, 2019

In ES3.1 preview, Landscape will render default material if change landscape material by using material instance of landscape's material. Will render correct if using another material's instance ...

Engine Crashing with AMD R9 2 and 3 Series Cards

UE - Graphics Features - Sep 23, 2015

Multiple users are reporting crashes in the Engine when using an AMD R9 380 and 390 series cards. There was a request to have these cards added to compat lab for testing, but have not heard any upd ...