Crash when calling SetState inside state machine OnUpdate

UE - Anim - Sep 5, 2025

The crash happens when SetState is called inside the function bound to OutputAnimationPose’s OnUpdate in the animation state. This way of using Set State node is the same as shown in the official do ...

Crash when using StaticDuplicateObject with mismathced Source and Destination class types

UE - Foundation - Jun 19, 2025

Starting in Unreal Engine 5.4, StaticDuplicateObject internally switched to using Unversioned Property Serialization (UPS) for performance reasons. However, UPS assumes the source and destination ob ...

An ensure is triggered when a StaticMesh is set inside a StaticMeshComponent on an actor, and another actor references the static mesh actor from two child actor components.

UE - Framework - Blueprint - Feb 5, 2025

There is an issue when setting a Static Mesh inside a blueprint that it is referenced by another blueprint with more than one child actor. An ensure is triggered inside the engine, and there is a ...

"StaticFindFirstObject: Ambiguous object name" on delegates with timelines in packed level actors

UE - World Creation - Worldbuilding Tools - Level Instances - Jan 31, 2024

Copying a grouped MaterialInstanceParameterDetail property that has spaces on it's name does not enclose it in double quotes, and later pasting won't work as expected

UE - Rendering Architecture - Materials - Aug 24, 2025

Copying a grouped MaterialInstanceParameterDetail property that has spaces on it's name does not enclose it in double quotes, and later pasting won't work as expected. The licensee noticed this in a ...

Crash when displaying lumencards on map with many objects

UE - Graphics Features - Lumen - Aug 1, 2025

There is a thread conflict between FRDGBuilder execution in Background Worker and LumenVisualizer's LumenCard add/delete process. When lumen cards are displayed in a scene with many objects, a crash ...

USplineComponent::FindLocationClosestToWorldLocation does not function correctly with non-uniform scale

UE - Framework - Components - Jul 19, 2022

Licensee reports incorrect results with FindLocationClosestToWorldLocation when used with non-uniformly scaled spline components. ...

StructUtils plugin's `FInstancedStruct` in a CPP-defined struct in a `TArray` on an actor component defined in CPP and implemented in BP. Populating the instanced struct in an actor BP's class defaults breaks serialization of the class defaults.

UE - AI - May 30, 2025

Context Instanced structs are great for holding simple data with the main advantage they have is a low memory overhead unlike instanced objects. Problem The problem is in StructUtils plugin's `FIns ...

Crash when exiting editor before EditorUtilityTask completes

UE - Editor - UI Systems - May 29, 2024

If exiting the editor before the EditorUtilityTask completes, it crashes. It will not crash if canceling the UtilityTask and then exit the editor. The following implementation does not allow destruc ...

VisualizeTexture with the BMP flag causes a crash when any mip over mip0 is requested

UE - Rendering Architecture - Dec 18, 2024

When a mip level higher than 0 is requested in VisualizeTexture, the engine will crash. The root cause appears to be VisualizeTexture.cpp:924, on which an incorrect mip level is used to read a non-m ...