Niagara Regression - Looping particle with Spawn Burst Instantaneous on time 0.0 flickers for a frame between loops

UE - Niagara - Jul 16, 2025

Note: This worked correctly up to UE 5.4, but repros from UE 5.5 up to mainline latest. If a Niagara Emitter is set up with "Spawn Burst Instantaneous" on time 0.0, and the spawned particle(s) have ...

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 ...

Crash when clicking "Reset to Default" button on the Details Panel for the MaterialAttributeLayers material node.

UE - Rendering Architecture - Materials - Jul 15, 2025

This crash repros from at least UE 5.3 and up to latest. The following assert is hit: Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 1067] Array index out of bounds: 0 in ...

CPU Lightmass generates different lighting results on a landscape if executed via a commandlet vs through the editor

UE - Graphics Features - Jul 3, 2025

Building lighting via commandlet and via editor are giving different results. To prevent one method from polluting the other via Swarm cache, the cache needs to be cleared in between tests. ...

Edit Condition does not work properly when the structure is used as a key for Map

UE - Framework - Blueprint - Jun 19, 2025

When the structure is used as a key for Map in Blueprint, Edit Conditions does not work properly. It will be updated when you move the focus to a different location(ex. a component) and click the v ...

Significant hitch occurs when invoking ApplySettings on a UGameUserSettings object

UE - Graphics Features - Jun 18, 2025

Calling the ApplySettings method on a UGameUserSettings object results in a noticeable hitch, with severity proportional to the number of primitive components present in the scene. This hitch stems ...

TSR does not converge while using the color grading widget

UE - Editor - Applied Usability - Jun 17, 2025

TSR (and TAA) does not converge when interacting with the color grading widget, but while keeping the mouse still. This makes it real-time previews more difficult. The expected behavior would be tha ...

Distance Field Traveral system in Content Example visual accuracy degraded since UE4

UE - Content - Content Example - Jun 10, 2025

Beetles no longer swarm on demo station mesh (only on the ground underneath), and beetles walks inside the head mesh more often than they did in UE4.  ...

If the map isn't dirty, it shouldn't be marked dirty when switching to the Perspective camera

UE - Editor - Workflow Systems - Jun 5, 2025

Changing to the perspective camera from a locked camera calls FLevelEditorViewportClient::SetActorLock I'm not sure exactly why it sets the camera to the cached pilot transform and then sets it bac ...

GPU Lightmass no longer works with cascaded shadow maps

UE - Graphics Features - May 29, 2025

Since Unreal Engine 5.5 stationary lights have stopped working with GPU Lightmass when using Cascaded Shadow Maps. With Virtual Shadow Maps enabled on the project, GPU Lightmass works. This issue d ...