FLevelInstanceActorGuid::GetGuid issue in Multiplayer

UE - World Creation - Worldbuilding Tools - Level Instances - Feb 3, 2025

I am doing some runtime manipulation of data layers and I am running into a check failure due to a zero guid in FLevelInstanceActorGuid::GetGuid during multiplayer testing. When I debug FLevelInsta ...

Spline mesh crashing in FRayTracingDynamicGeometryCollection::AddDynamicMeshBatchForGeometryUpdate

UE - Graphics Features - Ray Tracing - Jan 31, 2025

A crash occurs when using ray tracing with spline meshes preceded by the following ensure : Ensure condition failed: NumCPUVertices <= VertexBufferNumElements  File: Engine\Source\Runtime\Renderer\ ...

Building Geometry Stops UTickableWorldSubsystem Ticking

UE - Gameplay - Jan 31, 2025

Can be mitigated by reopening the Level. There is a repro project provided by the licensee on the case ticket. ...

Lumen ignores Landscape Holes (Landscape Visibility) when Hardware Ray Tracing is enabled and Ray Lighting Mode is set to Surface Cache

UE - Graphics Features - Ray Tracing - Jan 31, 2025

Context Lumen is the default global illumination and reflections system. Lumen renders diffuse interreflection with infinite bounces and indirect specular reflections in large, detailed environments ...

Adding SmartObjectZoneAnnotationComponent to a blueprint actor causes a crash when building the package

UE - AI - SmartObject - Jan 30, 2025

If placing an actor with SmartObjectZoneAnnotationComponent added to blueprint actor in a level, it will crash when the level open. As a workaround, adding SmartObjectZoneAnnotationComponent to the ...

No warnings or errors if a UEnum has Bitflags metadata, but no Flags flag.

UE - Framework - Blueprint Compiler - Jan 29, 2025

The problem here isn't obvious: the native enum, EAnotherEnum, is missing the Flags flag for the UEnum. As a result, K2Node_GetEnumeratorNameAsString returns the max enum when it gets a combined fla ...

Bitmask ints can't be converted to strings

UE - Framework - Blueprint Compiler - Jan 29, 2025

While we do have an auto cast function that handles an int to string conversion, bitmask ints use a "bitmask" subcategory which thwarts are ability to find the cast function. ...

K2Node_GetEnumeratorName doesn't support bitmasks

UE - Framework - Blueprint Compiler - Jan 29, 2025

This is almost identical to [Link Removed]. The difference is that we need a variant of UEnum::GetNameByValue that supports bitmasks. We'll likely have to run this by Core. ...

Bindless Textures do not mip stream as expected

UE - Rendering Architecture - RHI - Jan 29, 2025

Bindless textures do not appear to stream mip levels. This issue is separate from an already reported bindless virtual texture streaming issue. When the editor is freshly launched or when mip level ...

When changing the Visibility of a RetainerBox wrapped widget to “Not Hit-Testable(Self&AllChildren)”, the widget incorrectly accepts the hit test

UE - Editor - UI Systems - UMG - Jan 28, 2025

The result of changing the Visibility of a widget placed as a child of RetainerBox is not reflected. Here we have disabled hittest for the Button widget, but hittest is incorrectly accepted. This is ...