Level Instance Property Override: Actor::Tags overridden pre-CS but clobbered by RerunConstructionScripts with no post-CS re-apply

UE - World Creation - Worldbuilding Tools - May 4, 2026

Summary When using the Level Instance Property Override system, overrides applied to `AActor::Tags` are silently lost for Blueprint actors whose Construction Script assigns or appends to `Tags`. The ...

5.3 crashes when loading a map with an actor that had the class of one of its components changed

UE - Gameplay - Components - Feb 1, 2024

Create a blueprint based on actor, give it a SceneComponent named ExampleComp (BP_TestActor) - this should be the blueprints only componentCreate a new level (TestMap), place an instance of the bluepr ...

Setting Lightmap Coordinate Index Past 3 Causes Mesh to Get No Lightmap Information

UE - Graphics Features - Nov 20, 2018

Meshes with their Lightmap Coordinate Index set to anything over 4 will not be lit by static or stationary lighting.  Found in CL# 4.19 4033788, 4.20 CL# 4369336, 4.21 CL# 4541578, 4.22 CL# 4573698 ...

Fix iterative cooks to keep track of CookAdditionalFiles and delete them when the package file that created them is invalidated

UE - Core - Data Pipeline - Cooker - Sep 23, 2022

A licensee reports they are using the CookAdditionalFilesOverride function in UObject to add files to the project. This file is properly copied into the Staging area during Packaging, and is appropr ...

Custom iOS icons don't appear on device for Windows BP projects (Binary Build)

UE - Platform - Mobile - May 4, 2018

iOS icons have stopped working for Windows BP projects again; this does not occur on Mac. It also does not occur when using a source build from p4 (only on a binary build from the launcher). Note t ...

Skeletal Meshes do not work properly on Open GL ES 3.1 on Xiaomi Redmi 6

UE - Platform - Mobile - Oct 30, 2018

Skeletal meshes do not render or animate properly on the Xiaomi Redmi 6 (PowerVR GE8320) when using OpenGL ES3.1. This issue changed a bit from 4.19 to 4.20. In 4.19, the skeletal mesh seems to of ...

Physics simulation shows strange behavior with specific skeletal mesh configurations

UE - Simulation - Physics - Mar 3, 2017

PhAT is inconsistent on when it does and doesn't apply scale to Constraint positions. This leads to cases where the positions provided create constraints that may not work when the Preview Skeletal ...