Import then cancel while file is read leads to potential crash

TM - Interoperability - Oct 6, 2025

1/ Import a file with mootools such as an fbx 2/ while the file is still read, cancel the import Result : may crash few times after (when theoretically the file has finished being read) - not repr ...

Distant paint/scatter grass not rendered in PT exports

TM - Rendering - May 5, 2025

Reported in SF [Link Removed] In TM 2025.1.1, in PT renders with large amounts of scattered or painted vegetation, distant grass may not appear in exported renders that would previously appear in t ...

[CrashReport] Linux crash - TOpenGLBuffer<FOpenGLBaseVertexBuffer, 34962u, &()

UE - Platform - Linux - Sep 14, 2017

This is an infrequent Linux crash that has affected a few users in 4.17.1 Callstack from Log[2017.09.12-17.23.41:651][ 0]LogRHI: OpenGL MajorVersion = 4, MinorVersion = 5, ShaderPlatform = GLSL_43 ...

Project does not cook with actors containing ModularSynth component

UE - Audio - Sep 11, 2017

A project does not cook with actors containing ModularSynth component. The error is a follows UATHelper: Packaging (Windows (64-bit)): Cook: LogWindows: Error: begin: stack for UAT UATHelper: Pack ...

CLONE - Project does not cook with actors containing ModularSynth component

UE - Audio - Sep 13, 2017

A project does not cook with actors containing ModularSynth component. The error is a follows UATHelper: Packaging (Windows (64-bit)): Cook: LogWindows: Error: begin: stack for UAT UATHelper: Pack ...

FStateTreeExecutionContext::GetDebugInfoString() outputs wrong info and crashes when using linked state trees

UE - AI - Debugging - Apr 17, 2025

When using State Trees, the AI Debugger can be accessed during play to show information about their current execution state. If a behavior tree is currently in a state that references a linked tree, ...

Quality settings should not affect landscape resolution

UE - LD & Modeling - Terrain - Landscape - Mar 10, 2015

Changing the quality settings (or having them change on you automatically in the editor) drops mips on landscape heightmap textures, which isn't desirable as it makes it look like there are collisio ...

Foliage radius does not affect other foliage assets

UE - World Creation - Worldbuilding Tools - Foliage - May 5, 2016

Setting the radius on a foliage asset does not prevent other foliage assets from being painted within that radius. Regression (no) issues (does) occur in 4.10.4 ...

SkelMeshMerge not working for meshes with >1 LOD

OLD - Anim - May 31, 2018

Reported on UDN (see Additional Info URL). Looking at code, we call USkeletalMesh::AllocateResourceForRendering for every LOD, but we should only call it once. Need to check if our SkelMeshMerge t ...

Actor Enable Collision does not affect ISM

UE - Simulation - Physics - Nov 12, 2020

The problem was reported via UE Bug Submission. I was able to repro with their provided test project. ...