NPC - Instances does not get updates from changes to the parent Niagara Parameter Collection in the editor

UE - Niagara - Oct 4, 2024

When an Niagara Parameter Collection (NPC) is selected as the parent Collection for an NPC Instance (NPCI), all of its current parameters are carried over to the NPCI with their current values as th ...

Destructible attached with a Physics Constraint have inconsistent physics

UE - Simulation - Physics - Destruction - Jul 26, 2016

Destructible attached with a Physics Constraint have inconsistent physics compared to a standard Static Mesh. This is also sometimes prevalent with Destructibles that aren't attached with a Physics ...

Opcode shader compilation error when using a TextureSampleParameterCubeArray node with hardware ray tracing enabled

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

Materials containing a cube array texture sampling node will not compile when hardware ray tracing is enabled. The shader compilation error indicates that an invalid op code was used: "Opcode Sample ...

Packaged Project with Media Player Asset 'From Memory' Crashes and Corrupts Project

Tools - Feb 9, 2015

There is no Callstack associated with this crash. And I was unable to reproduce this in main due to a known issue when switching the 'Stream Mode' to 'From Memory'. When packaging a project in 4.6. ...

"Select New Skeleton" window appears behind editor and gives error

OLD - Anim - Apr 21, 2015

When you select an asset that references a skeleton that has moved, the editor asks you to choose a new skeleton. When you choose Yes is it gives the message "The Anim Blueprint could not be loaded ...

Tilemaps with masked materials respond to lighting at incorrect directions

UE - Gameplay - Paper2D - Nov 19, 2018

Tilemaps using lit methods of rendering are subject to strange lighting behavior. If the material for the tilemap is using a 'masked' method of rendering.  Lighting will appear at incorrect angles. ...

[AI] WP Dynamic navmesh fails to rebuild tiles with actors that are loaded but not part of the base navmesh.

UE - AI - Navigation - Feb 18, 2025

WP dynamic navmesh does not properly react to actors or navigation modifiers that are loaded in areas that the navmesh has not yet streamed into. Although the actors/modifiers are not part of the ba ...

Memory leak when Lumen is disabled but r.MeshCardRepresentation=1

UE - Graphics Features - Lumen - Jul 29, 2024

When Lumen is disabled, but the cvar "r.MeshCardRepresentation" is set to 1, Lumen will continuously enqueue object removal from the Lumen Scene, without ever emptying the array of primitives to rem ...

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 ...

Editor 'Build All Levels' discards Volumetrics Lightmaps in persistent level

UE - Graphics Features - May 14, 2025

Building the level or lightmaps can clear the volumetric lightmap. In 5.5, this requires you to perform a full build, or a lighting only build with a BSP brush in the scene. In 5.6, all level build ...