Material slot assignment incorrect after mesh reduction completely removes all triangles from a section

UE - Editor - Content Pipeline - Asset Build - Apr 28, 2022

When mesh reduction results in a section becoming empty, the material slots are incorrectly assigned. e.g. if section 0 gets removed due to it having no triangles after reduction, then its material ...

Deferring Blueprint CDO construction at load time is leading to some data loss.

UE - Gameplay - Blueprint - Jan 27, 2023

Various licensees are reporting data loss on load due to the change that was made for [Link Removed] in which we now defer Blueprint CDO construction on load until the finalization phase. This issu ...

Extracting Sprites from Padded Non-Power of Two Textures are Offset

UE - Gameplay - Paper2D - Oct 12, 2015

Extracted Sprites are offset when importing a non-power of two sprite sheet, padding it to a power a two mode, and then using the extract function. You can see this offset clipping of the extracted ...

Distance calculation using World Position are rendering incorrectly when packaged or launched for iOS and Android

UE - Platform - Mobile - Jan 15, 2016

When using a calculating the distance between the Absolute World Position (Including Material offsets) and a set Vector value, the correct value appears rendering to a texture's UV in PC Mobile Prev ...

Crash on Mac when adding Convex Collision to a mesh converted from a brush

UE - Platform - Apple - Jun 6, 2017

This is one of the top Mac crashes occurring in 4.16. Caused by adding Auto Convex Collision to a mesh converted from a brush. Does not occur on Windows. User DescriptionsI was trying to add a conv ...

UKismetArrayLibrary::GenericArray_Shuffle is weighted to return some results more than others

UE - Gameplay - Aug 15, 2017

The implementation of UKismetArrayLibrary::GenericArray_Shuffle() will generate certain array shuffle results more often (up to three times as much) than others, rather than having a roughly equal c ...

[CrashReport] ULevel::GetWorldSettings() - UMaterialInstanceThumbnailRenderer::Draw

Tools - Aug 29, 2017

This is a common assertion that has occurred since at least 4.14 and affected nearly 100 users. The callstack is similar to [Link Removed], which was marked fixed for 4.14. User DescriptionsUndoi ...

Skeletal Meshes have physics collisions lag

UE - Simulation - Physics - Oct 2, 2019

Skeletal mesh's physics collision lag behind the actual mesh. It didn't matter if there was just a root bone or multiple bones/constraints. This doesn't happen when using static meshes. The effect ...

Changing the name of a native component results in a blank details panel

UE - Gameplay - Components - May 7, 2021

Much like [Link Removed] (which I'm backing down on my by design claim), there is an issue where if you previously referenced a component that no longer exists, the correct instanced subobject is lo ...

Subsurface Scattering Checkerboard with SceneColourFormat 3 (High Scalability) leads to a visual artefact when temporal upscaling is in use

UE - Graphics Features - Sep 30, 2024

Primarily visible at very low internal resolutions (25-33%), the SSS checkerboard with an RGB scene colour format (r.SceneColorFormat 3) causes a double-image artefact both internally and on the sil ...