Editor-only blueprints like WidgetBlueprint are not added to cooked asset registry class hierarchy

UE - CoreTech - Aug 10, 2022

Both the Asset Registry and Asset Manager look for all subclasses of UBlueprintCore and use that to search for blueprint classes and construct an inheritance hierarchy. This always works in editor b ...

Switchboard Unable to Launch Multi-User Slate Server in Launcher Builds

UE - Virtual Production - Tools - Switchboard - Jan 14, 2023

Switchboard is unable to launch the Multi-User Slate Server in launcher builds.  This is because the default install location has "Program Files and "Epic Games" in the path (aka folders with spaces ...

Animation attributes - user defined structs containing types defined in plugins cannot be registered

UE - Anim - Runtime - Dec 18, 2023

This issue is caused by us forcing user defined structs to be loaded as part of AttributeTypes::Initialize.  That is called after at the ObjectSystemReady run phase during engine initialization howe ...

Packed Level Actors will create ISMs with inverted normals when a portion of static meshes have negative scales. This is apparent with two-sided materials.

UE - World Creation - Worldbuilding Tools - Feb 17, 2025

Packed level actors will create ISM instances with inverted normals when the selection of meshes used to create the packed level actor contains a subset of meshes with negative scales. This is the ...

Bad references for Lighting Scenarios when moving Levels and Map Build Data Registry to different Folder

Tools - Feb 2, 2017

When moving Lighting Scenario Levels and their associated Map Build Data Registry to a new folder within the Content Browser, the references within the Levels tab are updated as [MapName_BuiltData]. ...

Subsurface Profile Materials That Are Illuminated By Particle Lights Render White

UE - Graphics Features - Feb 9, 2017

Due to the changes made to subsurface profile (implementation of full resolution skin shading) it now renders white or with heavily faded base colors under certain conditions. In this case it is wh ...

Crash when element is added to a map variable with unhashable key

UE - Gameplay - Mar 21, 2017

Crash when element is added to a map variable with unhashable key. An error is thrown on compile but an element can still be added under the Details panel of the variable. Crash Reporter: [Link Rem ...

[CrashReport] UE4Editor_Persona!FBoneDescription::SetScore() [bonemappinghelper.h:31]

OLD - Anim - Sep 14, 2017

This is a somewhat common crash that appears to occur only in 4.17.1 (possible regression?). Users have not provided any description of their actions when the crash occurs. Source Context 20 ...

Hierarchical and normal Instanced Static Mesh Components do not maintain PerInstanceRandom values when transforms are modified

UE - Graphics Features - Nov 6, 2017

When using PerInstanceRandom in a material that is applied to a Hierarchical or normal Instanced Static Mesh component, there are issues of the value resetting when certain transform operations are ...

Bug - Animations and Keep State Fail when scrubbing backward.

UE - Anim - Sequencer - Jan 30, 2020

If you scrub past an animation with keep state, and scrub into an animation with defaults everything is fine. When you scrub back to the animation with keep state, the animation breaks, until there ...