Issue during the CapturingScene phase when having Nanite mesh as source component for HLOD Generation

UE - World Creation - Worldbuilding Tools - Feb 17, 2026

When generating the textures for Approximate HLOD layers, the Nantie geometry is very low resolution, resulting in the captured textures fitting the actual HLOD geometry poorly. This creates visual ...

Directly opening a modified map asset of a streaming sublevel does not always force it to be reloaded (inconsistent with other map open behaviors)

UE - World Creation - Worldbuilding Tools - Feb 10, 2026

When the level currently being edited has unsaved changes and the user opens a new one, the Editor asks if the changes should be saved. If the user answers negatively, the level asset is reverted to ...

SimpleStreamableAssetManager: Memory Bloat/Leak in AssetIndexToBounds4Index

UE - World Creation - Worldbuilding Tools - Feb 3, 2026

Overview: A report has been received regarding a memory leak that eventually leads to OOM crashes when s.StreamableAssets.UseSimpleStreamableAssetManager=1 is enabled. In projects that utilize this ...

Crash when removing and re-adding instances to an InstancedStaticMeshComponent with PerInstanceCustomData.

UE - World Creation - Worldbuilding Tools - Jan 22, 2026

When using an InstancedStaticMeshComponent with PerInstanceCustomData, the number of float elements in the "Custom Data" array should always be equal to NumCustomDataFloats multiplied by the number ...

HLOD generation can run out of space in the FName table

UE - World Creation - Worldbuilding Tools - Nov 26, 2025

A licensee reported that generating the HLOD for his large WP based level is running out of space in the FName string table.  He tracked the source of the problem to CL 47064601. Upon inspection ...

WorldPartitionConvertCommandlet hits an assert when converting a persistent level that contains a sub-level with a landscape

UE - World Creation - Worldbuilding Tools - Nov 7, 2025

Context: The Window tab allows a user to open the Levels window in order to add a sub-level to a persistent level. For Unreal Engine 5.0 and beyond, World Partition has made the Levels window obsole ...

RuntimeCellTransformers can result in increasing the instance count when a BP instance is not destroyed.

UE - World Creation - Worldbuilding Tools - Oct 22, 2025

The problem is related to the SimpleConstructionScript that executes on the BP instances after the transformer.  The problem also happens at cook time as the SCS is executed when the package is sav ...

Crash when changing r.MaterialQualityLevel when FastGeo plugin enabled in cooked build

UE - World Creation - Worldbuilding Tools - Sep 5, 2025

The engine crashes when the r.MaterialQualityLevel is changed in a cooked game that uses the FastGeo Streaming Plugin. The crash doesn't repro with the same steps in Editor, just in a cooked build. ...

Crash when running "MAP REBUILD ALLVISIBLE" with hidden sublevels and then changing maps

UE - World Creation - Worldbuilding Tools - Sep 1, 2025

Running the MAP REBUILD ALLVISIBLE editor command when the current map contains hidden sublevels causes a crash upon changing maps. The issue seems to be related to hidden sublevels being cleared in ...

Interaction between sublevels and LevelSequences can break actors attachments hierarchy of the sublevel.

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

Having a LevelSequence opened and unhiding a sublevel can break the attachment hierarchy of the actors that are inside the sublevel. This also affects to the sublevel asset itself. ...