Instanced Actors: Editor preview don't show correct relative mesh transforms

UE - Engine Scaling - Mass - May 30, 2026

Context Actors can be converted into Instanced Actors via the IA plugin. During runtime and in the editor, an instanced actor’s visual is generated from the collection of StaticMeshComponents on th ...

Split Struct pins cause errors when a project is converted to 4.17

UE - Gameplay - Aug 11, 2017

Split Struct pins cause errors when a project is converted to 4.17. You are still unable to split struct pins even if a new variable is created for the struct. Only adding a new variable to the st ...

OSS Steam: SteamSocket listen connections do not work after poll group changes

UE - Online - Oct 25, 2021

In 4.27 the logic in SteamSocket.cpp which is part of the SteamSockets plugin was changed to use Poll Groups instead of a removed API function that checked all children of a listen socket. However,  ...

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

zComponent - Archive - 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 - Runtime - Animation - 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 - Engine Scaling - Streaming - 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 ...

Crash related to Vertex Painting - MeshPaint!CastChecked<AActor,UObject>()

Tools - May 23, 2016

This crash was reported on the UDN. Upon further investigation it has been experienced by a handful of different users throughout 4.11 and 4.12. JIRA logged for tracking despite unknown repro steps ...

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 ...