Incorrect NiagaraSystem passed to KillUnusedComponents in ReclaimWorldParticleSystem

UE - Niagara - Jun 10, 2025

In UNiagaraComponentPool::ReclaimWorldParticleSystem, the cleanup loop for WorldParticleSystemPools calls KillUnusedComponents with the reclaimed component's NiagaraSystem (Asset) instead of the sys ...

Sphere Reflection Captures overridden by Skylight

UE - Graphics Features - Jun 10, 2025

When using non-Lumen lighting and Screenspace reflections off, the skylight location overrides the Reflection Capture location during Build Reflections. This results in a Reflection Capture taken fr ...

Anim State Notifies Don't Consistently Fire Begin/End Events for Looping Anim Sequences

UE - Anim - Runtime - Anim Blueprints - Jun 9, 2025

If you have an Animation Notify State and set it up on an animation to start at the exact beginning of the anim sequence and finish exactly at the end (I have attached a picture of this). It doesn't ...

Niagara Scalability Crash When Processing Significance

UE - Niagara - Jun 4, 2025

Method FNiagaraScalabilityManager::ProcessSignificance() iterates on indices from Context.SignificanceIndices and uses them to access the State and ManagedComponents arrays. It can then decide to cr ...

StructUtils plugin's `FInstancedStruct` in a CPP-defined struct in a `TArray` on an actor component defined in CPP and implemented in BP. Populating the instanced struct in an actor BP's class defaults breaks serialization of the class defaults.

UE - AI - May 30, 2025

Context Instanced structs are great for holding simple data with the main advantage they have is a low memory overhead unlike instanced objects. Problem The problem is in StructUtils plugin's `FIns ...

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 ...

Rendering of a Text Widget with Outline does not track LayerId correctly

UE - Editor - UI Systems - May 27, 2025

Text widget with Outline uses 2 LayerId levels to draw the outline and the text glyphs. This can be seen in function FSlateElementBatcher::AddShapedTextElement(), where lambda BuildFontGeometry() is ...

Virtual Shadow Maps on Spot Lights cause a blocky presentation similar to an incorrect mip level

UE - Graphics Features - Shadows - May 26, 2025

Spot Lights may present with very blocky shadow artefacts when a long attentuation radius is provided with a small cone angle. In extreme cases, this causes the VSMs to invalidate every frame. Notab ...

World Source in Take Recorder does not record auto-tracked actors properly

UE - Virtual Production - Tools - Take Recorder - May 23, 2025

The Take Recorder plugin allows for multiple sources to be recorded during gameplay. The World Source is expected to record everything in the level when the Autotrack Actors option is enabled. Once ...

Changes to Instanced Properties default value on BP not propagated to placed actors in the opened level

UE - Foundation - May 15, 2025

In UE versions 5.4 and onwards (as of CL 42589677 in Main), when an Instanced UObject property is defined in an Actor Blueprint, modifying the default value in the Blueprint does not propagate the c ...