Sampling textures with bias in the path of a custom data pin causes derivative operations when avoidable

UE - Rendering Architecture - Materials - Apr 8, 2025

Materials that make use of the analytical derivatives path to avoid hardware derivatives can still generate derivative operations on texture samples when the shading model has a custom data pin and ...

Calling UBlueprintMapLibrary::GenericMap_Find with a non-existent key causes a memory leak

UE - Framework - Blueprint - Apr 15, 2025

When Calling UBlueprintMapLibrary::GenericMap_Find with a non-existent key, the function construct the default structure in-place on the given pointer without destroying the object. This behavior ca ...

Chaos sometimes can not generate contact points while two dynamic convex hulls actually collide. It results in instability in the contact behavior​ - such as jittering, inconsistent contact forces, or unexpected collision responses.

UE - Simulation - Core - Dec 2, 2025

Context: Chaos Physics is able to use convex hulls to represent object collision geometry for queries and simulation. Problem: Chaos sometimes can not generate contact points while two dynamic conv ...

Breakpoint on SetText node in WBP PreConstruct triggers editor hang on save

UE - Gameplay - Blueprint - Apr 17, 2024

A user reported that when calling SetText on a text widget in a widget blueprint's PreConstruct causes an editor hang when you put a breakpoint on SetText and attempt to save the asset. The issue i ...

[CrashReport] UE4Editor_CoreUObject!HandlePlaceholderScriptRef() [class.cpp:1416]

UE - Gameplay - Blueprint - Nov 10, 2016

This Jira was created from CrashReports submitted by the public due to the high number of occurrences. Error message: Access violation - code c0000005 (first/second chance not available) Source C ...

Fbx animation re-import using UAssetImportTask in python will not use options

UE - Editor - Content Pipeline - Import and Export - Mar 5, 2021

Anim sequence re import factory is not overriding correctly the settings when we pass the override UFbxImportUI asset. It still use the original import data ...

MoviePipeline: Incorrect Caching of Min/Max World Delta Time

UE - Anim - Sequencer - MRQ - Jan 31, 2023

To test this issue: Create a C++ class WolrdTimeDilationDebugActor.h in your Project with the following code:// Copyright Epic Games, Inc. All Rights Reserved. #pragma once #include "CoreMinim ...

Custom Primitive Data types do not work with Procedural Meshes even though the option exists in their Details Panel

UE - Graphics Tools - Modeling Tools - Dec 16, 2021

This is a not a regression. Tested in UE5(Binary), UE4(Binary), and UE5 Main(P4). Procedural Meshes have the option for CPDs listed in their details panel under Rendering > Advanced >Custom Primit ...

VR Preview crash when shadow quality is set to low

UE - Platform - XR - Dec 5, 2024

[/Script/Engine.RendererSettings] r.Tonemapper.Sharpen=2 r.TemporalAA.Upsampling=False r.DefaultFeature.AutoExposure.ExtendDefaultLuminanceRange=True r.LightPropagationVolume=0 r.ReflectionCaptureRe ...

[CrashReport] UE4Editor_CoreUObject!FLinkerSave::FLinkerSave() [linkersave.cpp:31]

UE - Foundation - Core - Aug 22, 2017

This is a longstanding and common crash that has occurred since at least the 4.11 release. The error appears to occur while trying to access a .tmp file. User DescriptionsI left unreal unattended ...