Placing a section at the end of montage is not properly handled

UE - Anim - Gameplay - Feb 24, 2024

Placing a  section at the very end of a montage with no duration or animation assigned after it is not properly handled.  Normally sections with 0 length are skipped and search continues since they ...

FAnimMontageInstance::SetNextPositionWithEvents can trigger all notifies on a montage/sequence

UE - Anim - Runtime - Jun 24, 2025

This issue happens when Sequencer loops a dynamic montage. FAnimMontageInstance::ForcedNextFromPosition is set to 0 and ForcedNextToPosition is effectively the delta time. However, FMontageSubStep ...

Performance slowdown when ray tracing is disabled due to SetResidencyPriority

UE - Rendering Architecture - RHI - Jul 17, 2025

When a game is compiled with ray tracing disabled (D3D12_RHI_RAYTRACING=0) and the GPU the game is running on becomes low on VRAM, frame time is negatively impacted and doesn't recover. The D3D12_RH ...

Landscape Textures Patches issue when using "Texture Backed Render Target" as the Height Patch Source Mode where Landscape patches are not applying properly the first time a level is opened after restart

UE - Graphics Tools - Terrain - Landscape - Oct 6, 2025

Context: Landscape patches are components that can be attached to meshes to affect the landscape as the mesh is repositioned. Problem: The problem is that when using "Texture Backed Render Target" ...

Crash when removing cloth apb's assigned to asset

UE - Simulation - Physics - Character - Apr 27, 2016

When removing already assigned cloth asset from a skeletal mesh it will crash the editor. I was able to reproduce this with the Owen asset from Content Examples, but was unable to get it to work fro ...

Crash on Device when Deploying Mobile Project with Modulated Shadows and Planar Reflections on iOS 9

UE - Platform - Mobile - Jan 6, 2017

A crash occurs on iOS when deploying the licensee's project using iOS 9 version. The crash does not occur when deployed to a device using iOS 10 version. They believe the crash to be related to Pl ...

Hierarchical and normal Instanced Static Mesh Components do not maintain PerInstanceRandom values when transforms are modified

UE - Graphics Features - Nov 6, 2017

When using PerInstanceRandom in a material that is applied to a Hierarchical or normal Instanced Static Mesh component, there are issues of the value resetting when certain transform operations are ...

USplineComponent::GetDistanceAlongSplineAtSplineInputKey returns incorrect result when input keys are not sequential

UE - Editor - Workflow Systems - May 18, 2022

USplineComponent::GetDistanceAlongSplineAtInputKey() returns the wrong value when the input keys are not sequential because it interprets the input key argument as the spline point index. Thus if th ...

Electra video playback fails if project or package is under multibyte characters path

UE - Media Framework - Sep 16, 2022

The URL parser encodes the input path to a URL-encoded path even if it is local, so if the path contains unicode characters (such as Japanese Kanji ), the media file cannot be read. Following worka ...