Components tree is ending up with duplicate entries (same pointer added to the list view more than once), causing an assert

UE - Gameplay - Blueprint Editor - Jul 19, 2017

This is a common crash affecting users in 4.15 and 4.16. Over 200 unique users have been affected. User DescriptionsCamera Component Drag Drop Error 카메라 컴포넌트를 이벤트 그래프에 드래그 하는 도중 에러 발생 Creating a ne ...

EQS Overlap test no longer recognizes custom Collision Object Channel

UE - AI - Nov 12, 2019

Environment Queries Ignore tests for Custom Collision Object Overlaps. Note: The expected behavior seems to have worked in 4.21, After following the steps to reproduce, I can verify a successful de ...

Data Asset Deserialization crash after upgrading 4.19.2 to 421.1

UE - Foundation - Core - Feb 7, 2019

The User has provided an extensive log of their code base setup, and the process leading up to when the Assert occurs. "Our game mode & player state FSM are setup in a data driven manor using UDa ...

Landscape Splines in Partially Loaded World Partition Levels Can Cause Nanite Landscape Invalidation

UE - Graphics Tools - Terrain - Nov 7, 2025

Certain placements of landscape splines in world partition levels can cause Nanite landscape proxies to invalidate, and switch back to their non-nanite version. This happens when specific regions of ...

ChaosWheeledVehicleMovementComponent is breaking the const CDO contract and changes to the instances are being applied to the CDO

UE - Simulation - Gameplay - Apr 28, 2025

As described by the licensee, the const CDO contract is being broken on ChaosWheeledVehicleMovementComponent. The issue the licensee is facing is that by spawning cars with different configurations, ...

UClass::SparseClassDataStruct null at editor-time for child blueprints until compile

UE - Framework - Blueprint - May 29, 2024

Child blueprints of a blueprint of a native actor class with sparse data can have an incorrectly null SparseClassDataStruct value, and thus fail to initialzie their SparseClassData. This affects edi ...

Animation Sharing Plugin Removes Mesh Collision

OLD - Anim - Jun 11, 2019

The referenced documentation does not state anywhere about collision being affected by animation sharing nor is the user expecting it to be affected. Even when the Collision Preset is overridden to ...

When the engine version updated, partial data of TMap/TSet type of DataTable is missing

UE - Foundation - Core - Jan 7, 2019

When updating to 4.21, Element previously added to DataTable is missing. This only occur when you move to 4.21. If it change from 4.19 to 4.20, DataTable will keep data. it can restore broken data b ...

tvOS/IOS: Fails to Build with dSYM Options Enabled Due to DsymExporter Erroring Out

UE - Platform - Mobile - Jan 22, 2019

When attempting to package for tvOS or iOS with the generate dSYM options enabled, numerous instances of the following errors occur:[2019.01.21-20.53.35:739][138]UATHelper: Packaging (tvOS): [2019 ...

Disabling "Apply Fogging" Doesn't Work for Translucent Material with Volumetric Fog

UE - Graphics Features - Jul 6, 2018

Translucent materials with "Apply fogging" disabled will be affected by volumetric fog.  Found in 4.19 CL# 4033788, 4.20 Preview 5 CL# 4173640, and 4.21 ...