Subsurface Profile Materials That Are Illuminated By Particle Lights Render White

UE - Graphics Features - Feb 9, 2017

Due to the changes made to subsurface profile (implementation of full resolution skin shading) it now renders white or with heavily faded base colors under certain conditions. In this case it is wh ...

Material slot assignment incorrect after mesh reduction completely removes all triangles from a section

When mesh reduction results in a section becoming empty, the material slots are incorrectly assigned. e.g. if section 0 gets removed due to it having no triangles after reduction, then its material ...

Update Mesh Section incorrectly sets vertex colors for a Procedural Mesh

UE - Graphics Tools - Modeling Tools - Jun 21, 2022

This is a regression tested in //UE4/Release-4.27 CL#18319896 Update Mesh Section incorrectly sets vertex colors for a Procedural Mesh. The closer a colors R, G, or B value is to 1.0 or 0.0 the mor ...

[CrashReport] Assertion failed: TaskDataArray.Num() == Exporter->VolumetricLightmapTaskGuids.Num()

UE - Graphics Features - Lumen - Oct 2, 2017

This is a trending crash coming out of the 4.18 Previews. Users have not provided any descriptions of their actions when the crash occurred, but at least two of the affected projects are being creat ...

Bake To Control Rig on a Spawned Actor in a Subsequence with Play Range that exceeds the Subsequence causes a Crash

UE - Anim - Anim in Engine - Jun 28, 2023

This is a Regression. Tested in //UE5/Release-5.1 CL23901901 Using Bake To Control Rig on a Spawned Actor in a Subsequence with Play Range that exceeds the Subsequence causes a Crash. ...

Crash after creating a suboject for RootComponent if the actor is placed on the level

UE - Foundation - Cpp Tools - Hot Reload - Nov 6, 2020

The crash occurs when trying to assign a new value to RootComponent if the Pawn is already placed on the level Crash does not happen in  P4 //UE4/Release-4.25.3 CL 13942748 Other steps to reproduc ...

Curves in compressed additive animations interpolate incorrectly when two keys in a row have the same value

OLD - Anim - Oct 16, 2019

Curves compressed from additive animations will not interpolate correctly if they have two keys in a row with the same value. The second key will be ignored, leading to the curve interpolating earli ...

Crash retargetting AnimBP with "Allow remapping to existing assets" enabled

OLD - Anim - Aug 24, 2016

4.12 version of the crash: [Link Removed] Error message: Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 833] Array index out of bounds: 1 from an array of size 0 Sourc ...

Missing PSO Precaches in the engine

UE - Rendering Architecture - RHI - Aug 20, 2025

A licensee wanted to report some missing PSO Precaching they found, which they have fixed locally: 1. UCableComponent doesn't implement CollectPSOPrecacheData or call CheckPSOPrecachingAndBoostPri ...

Ambiguous Search Warning After Recompiling Blueprint of an Object Involved in a Level Sequence

UE - Anim - Sequencer - Apr 18, 2017

The licensee is receiving an ambiguous search warning after recompiling the blueprint of an object involved in a level sequence that is contained in a hidden sublevel (which is then loaded and made ...