UClass::SparseClassDataStruct null at editor-time for child blueprints until compile

UE - Framework - Blueprint - May 29, 2024

Child blueprints of a blueprint of a native actor class with sparse data can have an incorrectly null SparseClassDataStruct value, and thus fail to initialzie their SparseClassData. This affects edi ...

Blueprint fails to compile when adding new member to struct that is an input parameter of implemented interface function

UE - Gameplay - Blueprint - Jun 3, 2016

Adding variables to a structure that is an input parameter of an interface function causes a compile error in any blueprint that implements the interface until the interface is recompiled. Compile ...

Virtual Memory leak when using specific rendering settings in the template project

UE - Rendering Architecture - RHI - Dec 20, 2025

When a project is run with these settings in a template project, untracked virtual memory increases. Cvars r.GBufferFormat 3 r.Lumen.TraceMeshSDFs 1 r.Lumen.TranslucencyReflections.FrontLayer.Enab ...

When ParallelExecutor is enabled, Japanese build output of VisualStudio garbled

UE - Foundation - Cpp Tools - Sep 19, 2018

From UE4.20, Japanese build output of VisualStudio garbled. Below is a comparison between 4.19 and 4.20. ・4.19.2 1>------ すべてのリビルド開始: プロジェクト:MyProject3, 構成:Development_Editor x64 ------ 1> Clea ...

[Feature Request] CVars for HISMC

UE - World Creation - Worldbuilding Tools - Foliage - Jun 18, 2021

Currently some (if not all or most) foliage CVars affect both foliage and HISMC. It would be nice to split this so that users can change the values of one without affecting the other. ...

DestructibleMesh does not correctly effect vertex color of material.

UE - Simulation - Physics - Destruction - Oct 10, 2017

Destructible Mesh does not correctly affect vertex color. ...

Selected item in property matrix cannot be deselected

Tools - Aug 23, 2016

When selecting an item in the Property Matrix you cannot deselect. This affects changes you make that are supposed to be across all items selected by making them only affect the item selected. ...

Cascade Beam Emitter Lifetime Module Is Broken

UE - Niagara - Aug 3, 2018

Cascade beam emitter lifetime module is broken.  Working as expected in 4.19 CL# 4033788 Found in 4.20 CL# 4233996, 4.20 CL# 4247867 This is a regression. ...

Inaccurate updates to root widget visibility binding

UE - Editor - UI Systems - Apr 6, 2017

Inaccurate updates to root widget visibility binding, so far in my testing, this does not affect the functionality of the binding. Regression: affects 4.13.2, 4.14.3, 4.15.1 binary versions ...

Niagara Fails to Compile Shader For iOS and Android

UE - Niagara - Aug 2, 2018

Niagara fails to compile shader for iOS and Android. Unable to test in 4.19 due to assets provided being created in 4.20. Found in 4.20 CL# 4233996 and 4.21 CL# 4247867 ...