AbilitySystemComponent::NotifyAbilityEnded Can Crash due to Callbacks Invalidation Specs

UE - Gameplay - Gameplay Ability System - Oct 11, 2023

Pasting from the UDN: Unsafe code in AbilitySystem can lead to crash when granting an ability inside OnAbilityEnded Hello. We just ran into a crash. After investigation, it seems to be caused by ...

Gameplay Effects can hold stale references to GameplayTags when switching Gameplay Effect Component type

UE - Gameplay - Gameplay Ability System - Jan 9, 2024

Gameplay Effects can hold stale references to Gameplay Tags when the adding component is switched for a different type. The tags are serialised, and their presence can be confirmed with Reference Vi ...

Crash upon selecting CameraComponent in Sequencer when level is locked

UE - Anim - Sequencer - Aug 14, 2018

Selecting a Camera Component in the Sequencer window when the level is locked causes the Engine to crash.  This was reported and tested in 4.20.1 (CL-4233996). This was reproduced in 4.19.2 (CL-403 ...

Editor crash when enabling Distance Field AO Visualization in the Forward Renderer

UE - Graphics Features - Jan 9, 2017

When forward rendering is enabled along with Mesh Distance Fields if you go to visualize Distance Field AO in the main viewport the editor will crash. This only affects the Forward Render and works ...

Two-sided geometry cannot be enabled for re-imported models when converting from previous versions

TM - Interoperability - Jan 28, 2025

When converting files from previous versions of Twinmotion to Twinmotion 2025.1, re-importing any existing imported geometry will cause the geometry to be re-imported with two-sided geometry disable ...

GetTeamAttitudeTowards is called before AI Controller can spawn and gets a null value

UE - AI - May 6, 2019

Licensee is experiencing an issue where GetTeamAttitude is being called before the AI Controller's Construction event. This results in the warning "GetTeamAttitudeTowards - Pawn is null!" being outp ...

Morph targets unable to find B Material

OLD - Anim - Aug 2, 2016

Morph targets are not changing colors in some instances and just not doing anything in others(1.1 in Content Examples - MorphTargets) The output log is spammed with: LogMaterialParameter: B materia ...

Optimize Data Layer runtime state replication

UE - World Creation - Worldbuilding Tools - Data Layers - Dec 7, 2023

[Link Removed]This issue occurs only when I have a lot of RDLs (I tested 2500 and 1600). I tested with 6 RDLs and had no issuesI also noticed in the server log an error when a lot of RDLs are presen ...

Autobrake feature in ChaosVehicleMovementComponent is stopping vehicle from sleeping

UE - Simulation - Physics - Mar 5, 2025

In ChaosVehicleMovementComponent::CalcThrottleBrakeInput, autobrake is set when a vehicle is stopped - this means that when the car is virtually stationary, the BrakeOut inout parameter is always 1. ...

Capsule Indirect Lighting with ILCQ Volume breaks on Skeletal Meshes when making Sublevel visible not in the current Camera Frustum

UE - Graphics Features - Apr 12, 2017

When using Capsule Indirect Shadows for Skeletal meshes who have their ILCQ set to Volume, and loading a SubLevel with it's actors not within the current camera's view, the indirect lighting is blac ...