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 ...

Rarely, unmodified Niagara will cause diffs and bloat the patch.

UE - Niagara - May 3, 2022

Attached is a project that picks up Niagara from the content sample. The probability of reproduction is about 1/10. The simpler the project, the lower the reproduction probability. I am attaching ...

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 ...

Lightmaps on Mobile Devices Appear Dirtied and Pixelated

UE - Platform - Mobile - Jun 19, 2015

Baked lighting on mobile has dirtied or pixelated lightmaps. When testing this issue I attempted to change various settings within the 'Lightmass' section and the changes made did not have much effe ...

The "Random Integer in Range from Stream" returns the same value if the seed is power of 2 of anything above 22.

UE - Foundation - Core - Aug 7, 2019

When using the "Random Integer in Range from Stream" where the seed is a power of 2 after a certain point (2^22) the random integer that is returned is the always the same. If the seed is 2^23 + 1 i ...

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 ...

Enabling Shader compilation via XGE for 4.18 Editor downloaded from Launcher doesn't work, prevents shaders from compiling at all, editor from loading in some cases

UE - Foundation - Build - Rocket (Installed Engine) - Nov 9, 2017

If you enable Shader compilation via XGE by setting r.XGEShaderCompile = 1 in ConsoleVariables.ini in 4.18 Editor downloaded from Launcher, it prevents shaders from compiling at all, and as a result ...

Play Media Player Node Causes Blueprint Functions to be Uncallable

UE - Gameplay - Blueprint - Feb 23, 2016

This only occurs in standalone or a packaged game Having a Play Media Player node in a blueprint causes all of that blueprint's functions to become uncallable. Found in 4.11 Preview 5. Reproduced ...

Crash when spawning multiple HISM at runtime in a packaged shipping build

UE - World Creation - Worldbuilding Tools - HLOD - Feb 25, 2021

When adding multiple Hierarchical Instanced Static Meshes on a loop and packaging the project in Shipping configuration the application crashes due to LowLevelFatalError [Link Removed] [Line: 1431] ...

Opening a DataTable that is set to a Struct that is using a Key variable will crash the editor

Tools - Nov 3, 2015

Opening a DataTable that is set to a Struct that is using a Key variable will crash the editor User Description: I'm getting this crash when using Key variable in DataTable. I was able to repro i ...