Lumen Reflections in Stereo are broken after Nvidia GPU Driver Update

UE - Platform - XR - Jul 29, 2024

After updating the NVidia graphics driver to v.552.74+, reflective/mirror materials appear broken and render with black and white lines in VR mode if they are in a level with a Post Process Volume w ...

Modulated Self Shadowing can not be disabled for Static Meshes

UE - Platform - Mobile - Feb 6, 2017

Modulated Self Shadow is only ever disabled and enabled for Skeletal Meshes and does not have any effect on Static Meshes. You can use the command r.Shadow.EnableModulatedSelfShadow 1 to enable self ...

Cook fails when a MetaSound Source object is referenced utilizing FObjectFinder in C++

UE - Audio - MetaSounds - Apr 27, 2022

Android Cook fails when a MetaSound Source object is referenced utilizing FObjectFinder in C++ Repro Rate: 3/3 UATHelper: Cooking (Android (ASTC)): LogInit: Display: LogMetaSound: Error: Target int ...

Iris - Server fails to send client initialization RPCs after seamless travel if the client finishes travelling first

UE - Networking - Iris - Nov 18, 2025

During seamless travel, when a client loads into the destination level it will call APlayerController::ServerNotifyLoadedWorld, including when it finishes the travel before the server. When the serv ...

Geometry collection marked as nanite has no fallback in cooked build when nanite is disabled

UE - Rendering - Architecture - Dec 11, 2023

When geometry collection is set as nanite, there is no non-nanite render data cooked. This means that there is no fallback if the cooked build uses r.nanite 0. This used to work with some code worka ...

Local binary build of 4.22.1 fails when only Visual Studio 2019 is installed

UE - Foundation - Cpp Tools - Apr 30, 2019

Attempting to create a local binary build of 4.22 using Visual Studio 2019 (with no other versions of Visual Studio installed) currently fails with several warnings and errors, including the followi ...

Vertex Interpolators broken in landscape materials

UE - Graphics Tools - Terrain - Landscape - Aug 17, 2021

D:/Unreal/UE4_Release-4.27/Engine/Shaders/Private/LandscapeVertexFactory.ush(788,3-59): Shader FDebugViewModeVS, Permutation 0, VF FLandscapeVertexFactory[Image Removed]:/Unreal/UE4_Release-4.27/Eng ...

BP Event Dispatchers: Hidden reference from actor A -> B, if B bound to A's event dispatcher editor-time, unbound later, but actor A wasn't resaved.

UE - Framework - Blueprint Editor - Feb 19, 2026

Context In blueprint, one can bind to a referenced actor’s events by clicking an actor reference variable, and creating an event node through the variable’s detail panel. Under the hood, this adds ...

Reimporting of skeletal mesh results in a scrambled skeletal mesh

UE - Editor - Content Pipeline - Import and Export - Oct 17, 2025

When we reimport our skeletal meshes with updated FBXs, the resulting skeletal mesh is scrambled up. See Scrambled.jpg attached. This does not affect every single reimport but happens randomly. W ...

Crash when DFAO is disabled and a lower scalability is used while Distance Field Shadowing is enabled.

UE - Graphics Features - Feb 2, 2016

When enabling Distance Fields for a project and adjusting the cvars to disable DFAO and set a lower Detail Mode will result in a crash. Using the console commands outlined in the steps will work. ...