NormalizePackageNames() should interpret 'exclude developer folders' to also exclude packages in ExternalActors and ExternalObjects

UE - CoreTech - Oct 14, 2022

In NormalizePackageNames() (PackageUtilities.cpp), there is a PackageFilter parameter, which can be set to exclude developer packages (NORMALIZE_ExcludeDeveloperPackages). The code only checks the b ...

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" ...

VisualizeTexture with the BMP flag causes a crash when any mip over mip0 is requested

UE - Rendering Architecture - Dec 18, 2024

When a mip level higher than 0 is requested in VisualizeTexture, the engine will crash. The root cause appears to be VisualizeTexture.cpp:924, on which an incorrect mip level is used to read a non-m ...

Getting Fullscreen or Windowed Resolutions doesn't fully execute on Linux

UE - Rendering Architecture - RHI - Oct 28, 2019

When using "Get Supported Fullscreen Resolutions" on UE when built with Vulkan, no values are printed out. This is an issue with any platform that builds UE with -vulkan, not just Linux.  In Engine ...

Switching modular control rig to FK mode breaks pose of controls that have been baked to rig

UE - Anim - Rigging - Control Rig - Sep 14, 2025

From the licensee:We have built a modular Control Rig in Unreal 5.6, and while IK to FK matching works correctly inthe rig, but we are facing an issue when applying mocap animation to the characters ...

Crash when calling FillDataTableFromCSVString() while viewing the contents of the data table

When the function UDataTableFunctionLibrary::FillDataTableFromCSVString() is used from Editor Utility Blueprints or Python Scripts, and the contents of the affected Data Table are currently being vi ...

Multiple setter functions in UMaterialEditingLibrary always return false even when the parameter is correctly set on the MaterialInstance.

UE - Rendering Architecture - Materials - May 30, 2025

In Unreal Engine, materials can expose parameters that can then be modified via instances (MaterialInstanceConstant). The UMaterialEditingLibrary provides several functions to modify these parameter ...

Inconsistent texture loading issue within material editor

UE - Rendering Architecture - Materials - Jul 16, 2025

A licensee has reached out via EPS about a texture loading issue they are having in-editor. I summarized the most important points below:The issue relates to texture load failure associated with mat ...

Native variable references like GameplayAttribute cannot be searched by "Find in Blueprints" or "Asset Search"

UE - Framework - Blueprint Editor - Jan 4, 2023

"Find in Blueprints" does not turn up results when searching a GameplayAttribute by name, even when there is a GameplayEffect blueprint that has a modifier for that GameplayAttribute. This is becau ...

UNetDriver server-side hitch results in ActorInfo->NextUpdateTime far into future

UE - Networking - Feb 16, 2024

A high UWorld::Tick DeltaSeconds (i.e. GameThread hitch) results in a high UNetDriver::TickFlush DeltaSeconds. This DeltaSeconds can high (many seconds) if the hitch is long. This value then affects ...