Unreal Engine Issues
Unreal Engine Issues
Iris - large fast arrays serialize multiple elements when only one is dirtied
UE - Networking - Iris - Apr 8, 2025This seems to be a result of how the changemask is handled for fast arrays. Because the changemask is a fixed set of bits (defined by IrisFastArrayChangeMaskBits), a single bit can represent multipl ...
The hierarchy of Actors in LevelInstances can break when using BPs as parent
UE - World Creation - Worldbuilding Tools - Level Instances - Feb 18, 2026The hierarchy of a LevelInstance actors (Outliner) will break when cooking. The source is the call to AActor::RerunConstructionScripts in FWorldPartitionLevelHelper::MoveExternalActorsToLevel. The ...
When typing Korean in Slate using FTextInputMethodContext, characters outside a specific range are not entered
UE - Editor - UI Systems - Slate - Apr 7, 2026Descriptions After getting the below message LogTextStoreACP: Verbose: GetTextExt - From 33 to 34 A line break past that range is inserted. However, when typing Korean, the correct range is not s ...
USkinnedMeshComponent::FindClosestBone does not respect bRequirePhysicsAsset parameter
OLD - Anim - Mar 20, 2017A licensee has reported that the USkinnedMeshComponent::FindClosestBone function does not respect the bRequiresPhysicsAsset parameter, resulting in the bone returning bones that are not part of the ...
Mouse Events cannot be treated as Touch on Android Apps on Chromebook
UE - Platform - Mobile - Mar 18, 2019A licensee reported an issue where mouse events are not able to be used as touch events on Android apps. This was specifically reported on and tested on Chromebooks. After working with Chris Babcock ...
Deprecated components can still be added via the Add Component button
UE - Gameplay - Blueprint Editor - Oct 19, 2021The UDN has a possible fix for this issue in the Component Type Registry You can use the following as a test C++ class: #pragma once #include "CoreMinimal.h" #include "Components/ActorComp ...
UInstancedStaticMeshComponentRemoveInstances crashes if called with an empty array
This looks like it can be fixed with an early-out when the passed array of indices is empty. Log:[2024.01.03-16.38.36:091][291]LogOutputDevice: Warning: Script Stack (1 frames) : /Game/BP_Crashy.B ...
Calling GetMaterial during compile on load can cause the material shader to fail to compile
UE - Rendering - Architecture - Materials - Oct 4, 2024Calling UStaticMeshComponent::GetMaterial() during a Blueprint compile on load can cause the Material shader to fail to compile because GetMaterial will trigger a PostLoad call on that Material and ...
Windowed Fullscreen causes Lighting Variations in Rendered Envrionment
UE - Graphics Features - Jan 18, 2016When a scene is light with a single Stationary Directional Light and a Single Stationary Skylight and packaged to use Windowed Fullscreen, there is a difference in how the scene is rendered compared ...
Crash during PIE using the Spawn Actor node on EventBegin Play on Mac
UE - Platform - Apple - Feb 23, 2016A user has reported a crash when attempting to use the 'Spawn Actor' node within his level blueprint. I was able to follow the repro steps provided in the original answerhub post and get the crash ...