Morph Targets flicker Randomly in Slave Mesh

OLD - Anim - Oct 1, 2015

When a mesh is slave to a master mesh, its morph targets will flicker when Played in Editor. This does not occure with the same assets in 4.8. This has been reported by at least two different use ...

Crash when rendering cinematic in a Separate Process without "-NoLoadingScreen" cmd argument

UE - Anim - Sequencer - Jul 5, 2016

Crash when rendering cinematic in a Separate Process without "-NoLoadingScreen" cmd argument. Occurs in 4.12 and 4.13 in both Matinee and Sequencer Error message: Assertion failed: SizeX > 0 && S ...

FBX export from UE4 with multiple materials the UV is corrupted

Tools - Apr 18, 2016

When exporting a Static Mesh from within UE4 that has multiple materials, some of the material IDs will be condensed into a single ID which will mess up how the material assignment for that part of ...

Set Actor Location and Teleport from a Character when touching an Actor simulating physics will launch the Actor

UE - Gameplay - Jul 23, 2015

Set Actor Location and Teleport from a Character when touching an Actor simulating physics will launch the Actor. User supplied a video demonstrating the problem: [Link Removed] Test project in Pa ...

Crash when using Mesh Reduction on ScotsPine_01 for LOD3

UE - Graphics Features - Jan 30, 2017

A crash occurs when trying to use the Mesh Reduction tool for the ScotsPine_01 static mesh from the Open World Demo collection. The assets from this project are usually very processor heavy due to ...

When very far out from the map origin, large static mesh is not streaming in until player is close in world partition even though it's within loading range.

UE - World Creation - Worldbuilding Tools - World Partition - May 7, 2025

Context World Partition has a distance-based level streaming system that provides a complete solution for large world management. Problem The problem is that when the player and large static mesh a ...

Costs of Static Lights on Render Thread

UE - Graphics Features - Jun 9, 2016

A Japanese developer's making a scene that has over 4000 static point lights. They thought the lights don't affect rendering in runtime. But they realized the RenderThread's costs become bigger. I ...

[CrashReport]UnrealEditor-Chaos!Chaos::TEventContainer<Chaos::FCollisionEventData>::DispatchConsumerData() [EventManager.h:214]

UE - Simulation - Physics - Mar 14, 2022

Generated from CrashReporter Error Messages:Assertion failed: (Index >= 0) & (Index < ArrayNum) [File:D:\build\++UE5\Sync\Engine\Source\Runtime\Core\Public\Containers\Array.h] [Line: 691] Array ind ...

Vulkan leaks memory when opening and closing windows

UE - Rendering Architecture - RHI - Nov 22, 2019

As described here: https://udn.unrealengine.com/questions/532725/index.html (1) Start Prebuilt Vanilla 4.23.1. with Vulkan enabled (2) Create a new project (3) Drag and drop the Sphere from “modes ...

Using Attach To in Construction Script Causes the Editor to Crash

UE - Gameplay - Blueprint - Nov 17, 2015

After creating a blueprint with a box trigger and a cube component, attempting to use an AttachTo (Box) node and then attaching the cube to the In Parent socket compiles without issue. However, if y ...