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 ...

Playing sequences in reverse snaps after sequence has first ran

UE - Anim - Sequencer - Dec 29, 2016

I first came across this bug when I was working with Actor Sequences and noticed that the door I had opening would snap back when I tried to close it. Later I discovered that the issue was with play ...

Crash when adding multiple collision types to a mesh

Tools - Jan 27, 2017

Adding various collision types to a single mesh will cause it to hard crash the editor. No Crash Reporter window will open. Note that this happens with the user's mesh, but I was not able to repro ...

Subsurface Profile - Full resolution skin shading blows out results from ambient cubemap

UE - Graphics Features - Jan 12, 2017

Since the change to Subsurface Profile shader in 4.14 their use with ambient cubemaps have started giving blown out results that come back either white or very desaturated in the viewport. The curre ...

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 ...

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 ...