Niagara Mesh Renderer registers NumParticles x NumMeshVariants TLAS instances

UE - Rendering - Graphics Features - Ray Tracing - May 28, 2026

When using the Niagara Mesh Renderer with multiple mesh variants selected via MeshIndex, the number of TLAS instances allocated is NumParticles × NumMeshVariants and enabling the Path Tracer can ca ...

Regression - Nested scene component subobjects are no longer being registered when the owning scene component is added to an existing Actor instance as an instanced component.

UE - Gameplay - Components - Nov 16, 2016

This is a regression that was introduced with changes made to address issues with native vs. non-native component registration at Blueprint construction time ([Link Removed]). Prior to those change ...

SelectActorsUsingThisAsset doesn't select actors that are referenced by an array and using a Scene component as root

Tools - Sep 11, 2015

SelectActorsUsingThisAsset doesn't select actors that are referenced by an array and using a Scene component as root User Description: I have a BP with editable actor references array. Recently I ...

Landscape Resize Tool Stall

UE - Graphics Tools - Terrain - Landscape - Oct 3, 2023

From licensee: We're trying to reduce component count on our landscape using the resize tool. When modifying the landscape execution never completes. When I hit pause and get a breakpoint to see wh ...

Mobile Previewer: Safe Zone Invalid Until Window Resize

UE - Platform - Mobile - Jul 12, 2021

When the Mobile Previewer loads, the Safe Zone widget is not working properly at startup, and requires a window resize to update to the correct Safe Zone. ...

Using dynamic bindings in a code class will result in the bindings becoming a permanent part of any Blueprint created from that class if a hot reload is performed.

UE - Foundation - Core - Mar 26, 2015

If dynamic bindings are being used in a custom code class from which Blueprints are derived, any hot reload will make the bindings a permanent part of the Blueprint and they cannot be removed or cha ...

IOS crash disabling idle timer when closing the app

UE - Platform - Mobile - Apr 29, 2020

Licensee report of crash during shutdown due to setting [UIApplication sharedApplication].idleTimerDisabledbeing from the Game thread. Grouped together with others items in [Link Removed] ...

Given specific, non consistent, network connections, replication of some data can result in incorrect values

UE - Networking - Nov 2, 2016

I appears to be possible to replicate a value and when the value gets to the client(s), it doesn't match what was sent from the server. In the project, ReplicatedActor is created by the Authority. ...

Unable to pass TMap or TSet as a parameter for a UFUNCTION

UE - Foundation - Core - Mar 2, 2017

Attempting to pass a TMap or TSet into a UFUNCTION as a parameter causes a compilation error. Removing the UFUNCTION declaration works. Error messages:2>D:\Unreal Projects\Main\MyProject14\Source\M ...

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 ...