Crash when a Deferred Decal (Translucent) base material has a Nanite Override (Masked Surface) Material and the mesh has Nanite + Ray Tracing enabled.

UE - Graphics Features - Ray Tracing - Aug 14, 2025

A crash occurs when Nanite override material instance is used in a project with Ray tracing enabled where: 1 The Material assigned to the static mesh uses Deferred Decal / Translucent and the Nani ...

GenerateProxyMesh causes incorrect transform in ISM using Scale

UE - World Creation - Worldbuilding Tools - HLOD - Aug 20, 2019

MeshVertex has been converted by component transform before being converted by instance transform. It is ( Vertex * ComponentTransform ) * InstanceTransform. I thought it has to be converted by (Ve ...

FCDODiffControl doesn't properly account for lists of differing size.

UE - Gameplay - Blueprint - Sep 21, 2016

FCDODiffControl doesn't properly account for lists of differing size. The issues are marked in the following code:int IterOld = 0; int IterNew = 0; while (IterOld != OldProperties.Num() || IterNew ...

TickComponent and PostPhysicsTick in SkeletalMeshComponent can cause simultaneous read/write access

UE - Anim - Runtime - Jan 18, 2023

When a SkeletalMeshComponent is restarted by calling in order of   SetSimulatePhysics and SetComponentTickEnabled, the TickComponent and EndPhysicsTick are executed simultaneously. As a result, the ...

Crash due to D3D device being lost. (Error: 0x887A0006 - 'HUNG')

UE - Graphics Features - Feb 22, 2017

This JIRA has been made to consolidate all "D3D device being lost. (Error: 0x887A0006 - 'HUNG')" crashes into one. Previous Jira tickets include:[Link Removed][Link Removed][Link Removed][Link Remo ...

Packaging for HTML5 seems to have grown in package size

UE - Platform - Mobile - Aug 30, 2016

The size of packages for HTML5 has greatly increased since 4.10.4 to 4.11.2 and has since increased. Example: First person template, no starter content - size of whole HTML5 folder once packaged: 7 ...

SAnalogSlider moves slowly when step size is large

UE - Editor - UI Systems - Slate - Mar 6, 2024

SAnalogSlider calculates FastestStepTime by multiplying the step size value by a constant, resulting in high numbers for larger step sizes. This gets lerped from 1 and used as the repeat time, resul ...

BP timelines: when converting internal curve to external, the external curve isn't used until BP is recompiled

UE - Gameplay - Blueprint Editor - Aug 28, 2023

Blueprint timelines: when converting an internal curve to an external curve asset, the curve asset's data isn't used until the blueprint is recompiled. This is confusing as there is no indication th ...

SetCollisionProfileName and SetCollisionEnabled aren't working in Construction Script

UE - Simulation - Physics - Dec 5, 2019

This is a regression from 4.22.3 (CL-7053642) where this setup executed as expected. Toggling Collision Profiles in 4.23.1 (CL-9631420) and onward do not affect the Static Mesh and it acts as if it ...

AnimNotify triggering all play sounds at once in Matinee Animation Track

OLD - Anim - Jul 21, 2015

Placing a series of Play Sound Anim Notifies in an Animation and looping or playing that animation via Matinee multiple times causes the sounds to play all at once at the initial trigger of the anim ...