Pose watches don't display correctly with compatible skeletons

UE - Anim - Runtime - Anim Blueprints - Aug 19, 2022

"Hello, we've found a quirk with ABP's pose watch and compatible skeletons. Same setup as above. We have skeleton A as the base and skeleton B as a compatible skeleton. They both share similar hiera ...

Iris - large fast arrays serialize multiple elements when only one is dirtied

UE - Networking - Iris - Apr 8, 2025

This 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 ...

Cannot Add Collision to an EQS Testing Pawn

UE - AI - Jan 6, 2016

Attempting to add collision to an EQSTestingPawn class is not possible, as the inherited capsule component seems to override any new collision. Simulating with the inherited capsule will cause the P ...

USkinnedMeshComponent::FindClosestBone does not respect bRequirePhysicsAsset parameter

OLD - Anim - Mar 20, 2017

A 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, 2019

A 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, 2021

The 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, 2024

Calling 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 ...

Crash during PIE using the Spawn Actor node on EventBegin Play on Mac

UE - Platform - Apple - Feb 23, 2016

A 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 ...

Simple HUD in Topdown template will have rendering errors if played in Immersive mode

Tools - Feb 27, 2015

Simple HUD in Topdown template will have rendering errors if played in Immersive mode (F11). It will cause a white flickering line on the left and top of the window that will start to blur as the p ...