In 5.6, bWarningsAsErrors does not work with clang

UE - Foundation - Cpp Tools - UnrealBuildTool - Sep 20, 2025

In 5.6, many warnings and errors specify their command line arguments to the compiler with these new C# attributes:    [WarningsClangToolChain(["-Wno-date-time"], ["-Wdate-time", "-Wno-error=date-ti ...

Ray tracing scene doesn't reflect WPO with instance custom data

UE - Graphics Features - Ray Tracing - Sep 19, 2025

When custom instance data is used to calculate WPO in a Material and applied to an ISM the WPO value in the Lumen scene (ray tracing scene) is different than the visible scene resulting in incorrect ...

Ensure when calling server RPC from BeginPlay for a component that is not replicated by default

UE - Networking - Sep 18, 2025

This seems to occur due to the order in which the component is registered and set to replicate in UActorComponent::OnCreatedFromReplication. The component is first registered with the world, which c ...

Seam visible when using a material with BumpOffset on a Nanite mesh

UE - Graphics Features - Nanite - Sep 18, 2025

When a material that uses BumpOffset is fed into the Emissive Color of Surface Opaque Default Lit material and then applied to a nanite mesh, a visible seam can be seen along edges and the intersect ...

Nanite Skeletal Meshes Invalidate VSM

UE - Graphics Features - Nanite - Sep 17, 2025

Nanite Skeletal Meshes will always invalidate VSMs, even with their Shadow Cache Invalidation Behavior set to Rigid. This does not match the behavior of non-Nanite Skeletal Meshes. ...

Controller::OnPossessedPawnChanged broadcasts (Pawn->null) but not (null->Pawn) during AGameModeBase::RestartPlayer()

UE - Gameplay - Sep 17, 2025

Context AController has a blueprint assignable delegate that fires when the possessed pawn changes. This should fire in both singleplayer and networked games. The bug is reproducible in single play ...

Hovering items at bottom right of Content Browser does not display tooltip and causes cursor flicker

UE - Editor - Applied Usability - Sep 17, 2025

When hovering over items located at the bottom right corner of the Content Browser while the Editor is maximized, the tooltip is not displayed. It seems that the tooltip would extend beyond the edge ...

Point light missing issue on PowerVR GE8xxx when GPUScene is enabled

UE - Platform - Mobile - Sep 17, 2025

On PowerVR GE8xxx devices (e.g., GE8320), running with GPUScene enabled on the OpenGL ES path, point/local Lights render nothing or significantly weak result. Withouy GPUScene(UniformView/UBO path), ...

Painted foliage in a level instance can be selected in Foliage mode if the level instance is in main level, and foliage is duplicated if moved.

UE - World Creation - Worldbuilding Tools - Foliage - Sep 16, 2025

Context Foliage Mode is a set of tools that enables you to quickly paint or erase sets of Static Meshes or Actor Foliage. Level Instancing is a level-based workflow designed to improve and streamlin ...

Local Exposure can cause large variations in PreExposure under certain conditions

UE - Graphics Features - Sep 16, 2025

PreExposure is influenced by LocalExposure in PostProcessEyeAdaptation.cpp:1265. It appears when the scene is particularly dark and using manual exposure, the LastAverageLocalExposure can read a lar ...