Crash when cooking landscape collision in world partitioned level

UE - Graphics Tools - Terrain - Landscape - Jun 24, 2022

This is caused by the loss of data in the ULScapeHeightfieldCollisionComponent::CollisionHeightData. The CollisionHeightData is not marked as BULKDATA_PayloadInSeperateFile and is processed with a k ...

Integer overflow in NaniteBuilder can lead to an editor crash on certain meshes

UE - Graphics Features - Nanite - Jul 10, 2024

NaniteBuilder uses an int8 type for ExternalEdges and counts adjacency with a int32. The bug stems for the cast to int8 when adding the adjacency count into the ExternalEdges array. The precision l ...

Moving objects in editor does not update collision

UE - Gameplay - Apr 7, 2015

When an object is created procedurally with code and placed into the editor the collision analyzer will detect the object properly. If the object is then moved to another part of the level the coll ...

Indirect lighting cache generates points inside interpenetrating static meshes

UE - Graphics Features - Jun 10, 2015

Seems to be an issue with the indirect lighting cache where if you have interpenetrating static meshes (for example static mesh rocks that make up the ground), there are cases where the cache points ...

Blueprint inheritance can cause dangling references to stale UProperties across compiles

UE - Gameplay - Blueprint Compiler - Jun 6, 2017

A number of places in the code rely on raw UProperty pointers to track properties they care about. This can present issues when BPs inherit from other BPs, because the parent's class may be Purged / ...

LogAudioMixer warning results in a decrease of performance

UE - Audio - May 21, 2020

Unable to reproduce. User believes it is directly related to the speaker they are using when it goes into standby mode. If they unplug the speaker, everything runs okay.  After receiving the warning ...

GAS: Double attributes not shown GameplayDebugger

UE - Gameplay - Gameplay Ability System - Aug 27, 2025

Context The Gameplay Ability System lets devs specify numerical attribute properties in UAttributeSet subclasses. Although the preferred attribute property type is FGameplayAttributeData, GAS has l ...

Duplicating / Moving (to another level) an actor with a Hierarchical Instanced Static Mesh component causes a crash

UE - Graphics Features - Nov 14, 2016

When you have an actor with a Hierarchical Instanced Static Mesh component that has a Static Mesh set and is populated with at least 1 instance and then duplicate it or move it to another level, it ...

Grandchild actor with IsEditorOnly enabled is duplicated during save the level.

UE - Gameplay - Components - Dec 6, 2019

IsEditorOnly is not reflected in grandchild actor when parent/child/grandchild are constructed with ChildActorComponent. This causes the issue that actor will increase incorrect when save the level. ...

A hidden dedicated server is launched when playing as client

UE - Networking - Jul 15, 2020

When we play in editor with the Play Net Mode set to Play as Client, a hidden dedicated server is launched. Previously in 4.24 the dedicated server would always launch with a visible command window. ...