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 ...

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 ...

LogUMG: Error: The requested size for SRetainerWidget is 0. W:739 H:0 when opening or updating a curve using the StackedCurve view

UE - Anim - Sequencer - Feb 6, 2023

The following error is generated in the Output log whenever a Wave Table is opened or any of the graphs are modified. It also occurs when adding an Input to a Sound Modulation Parameter patch or add ...

Crash occurs when a Const Vector 4 and a Screen Position node are passed into a LERP then connected to the Result Node

UE - Rendering Architecture - Materials - Oct 13, 2022

Tested in: //UE5/Release-5.1 CL22346211 Crashed with Assertion //UE5/Release-5.0 CL20979098 Crashed with Assertion Crash occurs when a Constant Vector 4 and a Screen Position node are passed into a ...

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 ...

Motion Controller Components Don't Track Motion Controllers

UE - Platform - XR - Jan 17, 2020

The motion controller component doesn't track motion controllers correctly. This worked in 4.23. If you create a VR template project and follow the repro steps this issue doesn't occur. This was t ...

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. ...

Blueprint Viewport Not Updating When Destructible Mesh Component is Assigned a Mesh

UE - Simulation - Physics - Destruction - Apr 18, 2016

When you add a Destructible Mesh to a Destructible Mesh Component inside of a blueprint, the viewport is not updated with the new mesh. If you add the blueprint to the level and then open the bluepr ...