Custom Primitive Data color widget not applying correctly to static mesh components in Blueprint editor.

UE - Rendering - Architecture - Materials - Jul 23, 2025

Context Custom Primitive Data is used to store custom data in an index array that is accessible through Blueprint and code. This allows for variations across instances of the same mesh without needi ...

When exporting a level sequence (with its associated level) to USD, the asset paths for the reference are different from 5.5 and older

UE - Editor - Content Pipeline - USD - Jul 21, 2025

In 5.6, a referenced asset path looks something like         prepend references = @../../../../../Data/USD/Exports/FN-Main/ExportFolder/Assets/Sphere.usda@ instead of         prepend references = ...

Crash when opening a texture or editing its properties after stopping a preview in the material editor

UE - Rendering - Architecture - Materials - Sep 5, 2025

When a texture asset has certain properties edited, its PostEditChangeProperty() method calls to UTexture::NotifyMaterials(), which triggers a recompilation of materials that reference it in their m ...

Data like Camera Tracks can get corrupted inside Level Sequences when Undoing some operations

UE - Anim - Sequencer - Jul 22, 2025

Camera trucks can get in a invalid state when you undo certain operations. One example would be undoing a camera set that has been added to a camera track. When you undo that operation, other camera ...

ULevelInstanceSubsystem::CreateLevelInstanceFrom() is not honoring parameters bAlwaysShowDialog and LevelPackageName

UE - World Creation - Worldbuilding Tools - Level Instances - Aug 6, 2025

A Level Instance or Packed Level Actor can be created through editor scripting by using function ULevelInstanceSubsystem::CreateLevelInstanceFrom(), which receives parameters packed in the FNewLevel ...

Crash when clicking "Reset to Default" button on the Details Panel for the MaterialAttributeLayers material node.

UE - Rendering - Architecture - Materials - Jul 15, 2025

This crash repros from at least UE 5.3 and up to latest. The following assert is hit: Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 1067] Array index out of bounds: 0 in ...

Cloth Asset - Crash when importing morph targets into clothing

UE - Simulation - Visual - Oct 20, 2025

The sim morph import has been broken after a change to make it work for cooked assets. Ticking the Import Sim Morph Targets checkbox crashes as soon as a skeletal mesh with morph target is specifie ...

Child actor components fail to attach in cooked builds when mobility is set to movable and end up at the origin

UE - Gameplay - Oct 21, 2025

Context: A Child Actor Component allows an actor in Unreal Engine to contain another actor as its child (component). Problem: The problem is inconsistent handling of child actor component mobility ...

[PCG] Undoing the deletion of a pcg actor removes the Instance Category from the pcg component, specifically no graph parameter can be seen.

UE - World Creation - Procedural Tools - PCG Component - Oct 31, 2025

Context: PCGComponents on actors contains a category "Instance" that allows the user to connect a PCG Graph of their choosing to the PCGComponent which allows the Procedural Node Graph to sample the ...