Editing an array config property via ProjectSettings can end up editing other platform config properties.

UE - CoreTech - May 27, 2024

Platforms .ini config files can end up with incorrect data, due to how ProjectSettings manages the config data. On a Windows machine, if we open the ProjectSettings window, all the data is going to ...

When an active Niagara Component is moved and reset+reactivated in the same frame, "Interpolated Spawning" causes "Spawn Burst Instantaneous" to spawn particles in the previous frame's outdated location

UE - Niagara - Mar 6, 2024

Consider a Niagara System with an Emitter in "Global Space" that has "Interpolated Spawning" active and a "Spawn Burst Instantaneous" module with a "Spawn Time" of 0.0 (for example, the built-in Con ...

World Partition - Deleted actors can become unloaded prior to saving

UE - World Creation - Worldbuilding Tools - World Partition - Apr 11, 2025

In world partition levels, deleted actors can become unexpectedly unloaded prior to saving, causing loss of work. Specifically, this issue occurs after the undo history has been cleared (either manu ...

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 ...

Properties not serialized when moving actor/component depending on unrelated specifiers

UE - Framework - Blueprint - Sep 25, 2023

When an actor is moved on the level editor viewport, it is reconstructed along with its components, which at first makes their properties reset to their default state. Thankfully, this does not happ ...

Geometry Collection cluster handles leaking and causing ensures with field systems

UE - Simulation - Physics - Destruction - Aug 26, 2025

Geometry Collection cluster handles leaking and causing ensures with field systems. The licensee has shared their analysis: We have been tracking down an assert that seems to happen occasionally wh ...

Culling Distances Not Working For Static Mesh in Procedural Content Generation Tool and Foliage Tool

UE - World Creation - Procedural Tools - Mar 28, 2025

When creating Foliage or Procedurally Generated Content the culling settings of the Static Meshes do not apply correctly. As soon as either a minimum or maximum cull distance is set the Static Meshe ...

In editor, sub level instance's streaming state persists incorrectly after toggling Level Behavior without saving

UE - World Creation - Worldbuilding Tools - Level Instances - Jun 11, 2025

When adding a sub level with world partition streaming to a main level where the streaming is also enabled, setting* Level Behavior* of the sub level to Standalone, and saving the result, in the fir ...

Implied Decal Blend Modes don't properly account for Material Attributes usage

UE - Graphics Features - Sep 28, 2021

I've attached a project with the necessary materials that demonstrate this issue. I would expect that just because a Set Material Attributes node is inside a material graph it wouldn't affect the de ...

Custom UVs don't store information properly in layered materials.

UE - Rendering Architecture - Materials - May 9, 2022

[Link Removed] I have this set up so that FX artists can stack UV manipulations, so I don't want to just have all the UV manipulation in the layer with the base color, even though that does give me ...