ChaosCacheManager is not properly recording the state of each particle when toggling Fields and Anchor Fields in the scene.

UE - Simulation - Physics - Destruction - Oct 22, 2024

ChaosCacheManager is not properly recording the state of each particle when toggling Fields and Anchor Fields in the scene. During my investigations I've noticed that ChaosCacheManager does not reco ...

Option "Use Mouse for Touch" does not work correctly when running the game in "Standalone" or "New Editor Window (PIE)" modes: Virtual joystick does not appear and mouse cursor is incorrectly hidden while captured.

UE - Gameplay - Input - Apr 1, 2025

The Editor provides option "Project Settings – Engine – Input – Mouse Properties – Advanced – Use Mouse for Touch" to allow testing virtual joysticks and other touch controls with the mouse. When ru ...

FRayTracingGeometryManager::Tick() called twice during a single frame

UE - Graphics Features - Ray Tracing - Mar 5, 2025

UDN licensee Prophecy Games has encountered an issue in which the RaytracingGeometry::Tick() function is called twice during a single frame. This causes an assert to trigger, which blocks them from ...

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the same frame, "Interpolated Spawning" causes "Spawn Burst Instantaneous" to spawn particles in the previous frame's outdated location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 ...

UEdGraph pointer data is not correctly un-done and graph nodes are lost when declared as a UObject property

UE - Framework - Blueprint Editor - Aug 9, 2024

When an undone operation is done for a UObject property that has a UEdGraph*, the modified UEdGraph nodes are lost. This UObject needs to be created/spawned in an Editor Environment by another Obje ...

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 ...

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 ...