FIOSInputInterface::SendControllerEvents crash due to UIInterfaceOrientation call from game thread

UE - Platform - Mobile - Apr 29, 2020

From [Link Removed], licensee reports We believe that querying the UIInterfaceOrientation via UIApplication on the game thread is the issue here. We have made changes to IOSInputInterface.cpp and I ...

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 ...

AddChildActorComponent in Construction Script Causes Pending Kill Error

UE - Gameplay - Blueprint - Feb 16, 2016

When using AddChildActorComponent in the construction script of an actor and attempting to get a reference to the child actor that is stored in a variable on Event Begin Play, the editor throws erro ...

Details panel for Actor Component is blank in any Blueprint that derives from a code class using that Actor Component after the Actor Component's class name is changed

UE - Gameplay - Blueprint - Dec 20, 2018

Changing the name of an Actor Component code class in a project results in any existing Blueprints that derive from code classes that use that Actor Component to not display the Actor Component's pr ...

Crash while using Geometry Scripting to add an Array of Vector 2D data to 'Append Buffers to Mesh' node UV0 input pin

UE - Graphics Tools - Modeling Tools - Jun 13, 2022

Geometry Scripting plugin isn't available for 4.27.2, and the behavior is the same 5.0.1. Crash while using Geometry Scripting to add an Array of Vector 2D data to 'Append Buffers to Mesh' node UV0 ...

Unexpected behavior occurs when the default elements of a TMap in an Actor Component are modified in an instance of a Blueprint containing that Actor Component

UE - Gameplay - Blueprint - Jan 17, 2017

Adding an Actor Component that contains a TMap property to a Blueprint results in unexpected behavior when default elements of the TMap are modified in an instance of the Blueprint in the level:Addi ...

FSlateApplication::OnControllerAnalog triggers a MouseLeftClick event to be added to the input stack.

UE - Gameplay - Input - Jun 3, 2016

It appears that FSlateApplication::OnControllerAnalog triggers a left mouse click to occur on mobile platforms. If developers haven't properly avoided hooking up delegates to the InputComponent for ...

Blueprint Cannot Give Niagara CPU Access To Skeletal Meshes Added From Blueprint

UE - Niagara - Apr 4, 2019

When a user tries to add a skeletal mesh component to a blueprint with a niagara system to use the skeletal mesh with that niagara system, the niagara system will stop rendering because it does not ...

Issue during the CapturingScene phase when having Nanite mesh as source component for HLOD Generation

UE - World Creation - Worldbuilding Tools - Feb 17, 2026

When generating the textures for Approximate HLOD layers, the Nantie geometry is very low resolution, resulting in the captured textures fitting the actual HLOD geometry poorly. This creates visual ...

Ribbon Particle Normals are reversed from default Sprite Particles

UE - Graphics Features - Oct 13, 2015

It appears that the Vertex Normals from Ribbon Particles are opposite of what is expected via the Default Particle System given both systems share the same alignment (Facing Camera) [Image Removed] ...