Add support for motion data on SteamDeck (Steam Controller plugin)

UE - Gameplay - Input - Mar 7, 2025

We have a UDN user with a proposed change: https://udn.unrealengine.com/s/question/0D5QP00000yo70w0AA/add-support-for-gyro-motion-data-to-steam-controller-plugin?fromCase=1 Hi, we were adding gyr ...

LevelStreamingPersistence: BP added components don't persist properties in PIE until map actor resave

UE - World Creation - Worldbuilding Tools - Mar 6, 2026

Context The LevelStreamingPersistence plugin can be used to remember and restore properties on actors, components and other objects that are part of a streamed level. Persisted properties are resto ...

LayeredBlendPerBone without BlendRootMotionBasedOnRootBone exaggerates root motion

UE - Runtime - Animation - May 27, 2023

When BlendRootMotionBasedOnRootBone is false, the LayeredBlendPerBone is aggregating root motion of the child poses ontop of the base pose root motion.  (ie. if the first child pose's blend weight i ...

Prevent unnecessary rebuilds of windows resource files

UE - Core - Cpp Tools - UnrealBuildTool - Sep 20, 2023

How Necessary are BUILT_FROM_CHANGELIST and BUILD_VERSION in Resource Files? We've been investigating ways to improve the speed of our iterative engine builds, and have found that the vast, vast maj ...

Niagara Mesh Renderer registers NumParticles x NumMeshVariants TLAS instances

UE - Rendering - Graphics Features - Ray Tracing - May 28, 2026

When using the Niagara Mesh Renderer with multiple mesh variants selected via MeshIndex, the number of TLAS instances allocated is NumParticles × NumMeshVariants and enabling the Path Tracer can ca ...

TMap where key is an FString: initializer list will accept bad MakeTuple

UE - Core - Systems - Sep 2, 2026

POST LINK: https://forums.unrealengine.com/t/tmap-where-key-is-an-fstring-initializer-list-will-accept-bad-maketuple/2747443 POST BODY:Summary A TMap where the key is an FString can be created lik ...

Client Gameplay Effect stuck on due to duplicate ReplicationIDs

UE - Gameplay - Gameplay Ability System - Oct 31, 2025

We've been tracking down a problem recently with the Gameplay Ability System where a gameplay effect is properly removed on the server, but the client has the gameplay effect stuck on permanently. ...

[AI] Gaps between Nav Mesh tiles in World Partition map causing movement issues

UE - Runtime - Character - Nov 4, 2025

Navmesh has seams between some tiles that are actual edges rather than previously found "gaps" where it was a debug rendering issue. Pathfinding does fail between these tiles to go straight across. ...

[CrashReport] Mac crash - UE4Editor-Slate.dylib!FTextLayout::GetAsTextAndOffsets()

UE - Platform - Apple - Aug 15, 2017

This is a trending Mac crash in 4.17.0 that also had some occurrence in 4.16. Users have not provided any descriptions of their actions when the crash occurred, but the callstack is nearly identica ...

In some situations, a Blueprint can become devoid of an Event Graph. While no graphs are present, multiple variables can be created with the same name.

UE - Framework - Blueprint Editor - Aug 26, 2024

In some situations, a Blueprint can become devoid of an Event Graph, or be created without one from the start. For example, function "FKismetEditorUtilities::CreateBlueprint()" in UE 5.4 does not ca ...