CreatePatchLibrary is broken

UE - Rendering - Architecture - Shaders - Nov 12, 2025

It seems the FEditorShaderCodeArchive.LoadExistingShaderCodeLibrary missed some functions, use FEditorShaderCodeArchive.AddShaderCodeLibraryFromDirectory instead could fix the issue. ...

Megalights support for anisotropic materials

UE - Rendering - Graphics Features - Lumen - Apr 14, 2026

A licensee noticed that SUPPORTS_ANISOTROPIC_MATERIALS is not passed to FShadeLightSamplesCS::ModifyCompilationEnvironment for MegaLights ShadeLightSampleCS. Adding it fixes the issue. ...

Behavior tree assets marked dirty when opening in subeditor

UE - AI - Aug 16, 2016

Found while I was fixing up other content, that Behavior Tree assets are being marked dirty by just opening them into sub editor. ...

Moving or renaming a file in the editor should execute a Perforce move command not a delete+add

Tools - Aug 31, 2016

Moving or renaming a file in the editor erases its perforce history. It should execute a move not a delete + add to fix this ...

Hot reload iteration time regression.

UE - Foundation - Core - Oct 19, 2017

Hot reload iteration times have been crippled ever since CL# 3332960, which was a fix for [Link Removed]. ...

IOS-Shipping memory managentment failed for std::string

UE - Platform - Mobile - Oct 8, 2018

[Image Removed] [Image Removed] [Image Removed] if strip with -x option, it will fix this issue. ...

Movement broken for Top Down template for Clients

Docs - Samples - Jan 7, 2015

There is no way to control the player after creating a new top down project (blueprint or code). This should be fixed by [Link Removed] ...

Creating BlueprintActor from EmptyActor produces an Actor with multiple DefaultSceneRoots

UE - Gameplay - Blueprint - Jan 24, 2020

This does not happen with UE4.22. Maybe related to CL#7462096 and CL#7476283. These are fixes for [Link Removed]. ...

UserDefinedEnum variables in UserDefinedStructs aren't properly updated when the enumerations are reordered.

UE - Gameplay - Feb 4, 2020

UserDefinedEnum variables in UserDefinedStructs aren't properly updated when the enumerations are reordered. FEnumEditorUtils::BroadcastChanges fixes up Blueprints but not UserDefinedStructs.  ...

TSlateMaterialShaderPSDefault cast error when opening Platform Stats in Lyra's M_UI_Base_BordersAndButtons Material

UE - Rendering - Architecture - Materials - Jun 16, 2022

Licensee has provided a potential fix, please see the UDN link. Callstack attached utilised -onethread ...