UAbilityTask_SpawnActor::BeginSpawningActor may return true when SpawnedActor contains stale value

UE - Gameplay - Gameplay Ability System - Mar 15, 2026

UAbilityTask_SpawnActor::BeginSpawningActor assumes the incoming AActor*& SpawnedActor parameter is nullptr if no actor was spawned, but it does not initialize the parameter at the start of the func ...

[Audio Analysis][Ensure] - Sound Submix Spectral Analyzer Delegate Throws Ensure when Analysis Started Before the Delegate is Added

UE - Audio - Nov 25, 2021

Hit the following Ensure when trying to use the Spectrum Analyser. Also hit this in 4.26 so it doesn't appear to be a regression. Occurs with any of the following Band Settings or when creating you ...

WPO is incorrectly generated on materials using Material Attributes as input to Landscape Layer Blend node

UE - Rendering - Architecture - Materials - Jan 31, 2024

This comes from this UDN : [Link Removed] It occurs with this setup :  [Image Removed] , where Set Material Attributes expressions act as inputs to the Landscape Layer Blend material expression. ...

Direct Capsule Shadows with Point Lights also project shadow on opposite side and direction

UE - Graphics Features - Dec 14, 2016

When using a Direct Capsule Shadows on a skeletal mesh with a Stationary Point light, depending on the point lights placement, light source radius, and nearby surfaces will cast the shadow on the op ...

UE4Editor does not start when there are no audio devices available

UE - Platform - Linux - Sep 26, 2018

UE4Editor does not open when there are no audio input or output devices available. The editor hangs at 83% after it initializes the AudioMixer. This issue looks like it was caused by CL 4396954. Et ...

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 ...

WorldPartitionConvertCommandlet hits an assert when converting a persistent level that contains a sub-level with a landscape

UE - World Creation - Worldbuilding Tools - Nov 7, 2025

Context: The Window tab allows a user to open the Levels window in order to add a sub-level to a persistent level. For Unreal Engine 5.0 and beyond, World Partition has made the Levels window obsole ...

Packaging Error When Setting Recast Nav Mesh Runtime Generation

UE - AI - Jan 25, 2016

Setting the Runtime Generation on the Recast Nav Mesh to a different preset than what is set in the Project Settings causes an error to appear upon trying to package the project, and causes the pack ...

Light as If Static setting does not Persist when Re-opening Project

Tools - Apr 28, 2016

This bug was originally entered back in 4.8 as [Link Removed], but was closed as by design. The reason was, the mesh did not have Lightmap UVs, so using the 'Light as If Static' option would not wor ...

Child character's Variable changes to the default value in a packaged project

UE - Gameplay - Blueprint - Jun 22, 2015

Child character's Variable changes to the default value in a packaged project. User Description: Name of player character resets (to default value specified in parent class) after packaging. 3. P ...