Navigation data contained entirely within a Level Instance is not registered at runtime (PIE / standalone / packaged) in a World Partition persistent level

UE - Runtime - Character - Jul 13, 2026

A licensee is composing independently-authored levels into a single World Partition persistent level by placing each as a Level Instance. NavMeshBoundsVolume / NavModifierVolume are placed inside ea ...

WorldPartition RuntimeHashSet: non-deterministic URuntimePartitionPersistent UObject name causes unstable Cooked output (RuntimePartition:DebugColor)

UE - World Creation - Worldbuilding Tools - HLOD - Jul 9, 2026

During deterministic Cook / Package validation, the Cooked output of a WorldPartition map was found to vary non-deterministically between Cook runs. Diff detected in the DiffOnly Cook log:Serialize ...

Editor crashes in FAsyncLoadingThread2::ProcessLoadedPackagesFromGame when Level Blueprint references external actor

UE - World Creation - Worldbuilding Tools - Level Instances - Jun 26, 2026

Adding a reference to an external actor in the level blueprint causes the package for the actor to be put in the import table of the level. In some cases, the actor package can end up calling postlo ...

UserSceneTexture not working in Virtual Reality

UE - Platform - XR - Jun 25, 2026

User reports that UserSceneTextures used in Post Process Materials are only correctly rendered inside the left eye in VR. ...

Adjusting Vegetation Growth for Bushes in Media Mode alters their global size settings

TM - Tools - Jun 25, 2026

Reported in SF [Link Removed] When making adjustments to the Vegetation growth Season parameter inside Media Mode, if a scene contains Bushes then any adjustments to the Vegetation growth will adju ...

Parameter metadata not accessible if modified in Material Instance and then converted to CustomPrimitiveData

UE - Rendering - Architecture - Materials - Jun 24, 2026

There’s a potential issue with some changes we made to UMaterialInstance::GetParameterValue (https://github.com/EpicGames/UnrealEngine/commit/8f2bebb008ba645f5938da844cd46b0925322b13). It seems as t ...

Report: Crash when adding new object instances in array in Widget Editor

UE - AI Workflows - UI Systems - Jun 24, 2026

Please review crash report from EPS case. repro project attached [Link Removed] ...

Custom expression additional outputs don't work when connected to World Position Offset

UE - Rendering - Architecture - Materials - Jun 24, 2026

Custom expression additional outputs are considered (0,0,0) when connected to WPO. ...

The speed of Animators is increased in exports

TM - Tools - Jun 23, 2026

Reported in SF [Link Removed] When setting Animator tools to use Collision mode for video, the loop speed of the animator will be twice as fast as specified in the video export. Attached a sample ...

Translucent meshes randomly flicker when using VSM

UE - Rendering - Features - Jun 23, 2026

Flickering can occur on translucent materials, usually in the distance when there is at least one directional light and when using VSM. Flickering seems highly dependent on framerate and timing. L ...