HZB occlusion is broken on Instanced Stereo

UE - Platform - XR - Oct 2, 2025

Other engine features requiring HZB data (such as per-instance GPU LOD selection occlusion culling or light grid culling) are also impacted regardless of whether r.HZBOcclusion is enabled. ...

OculusOpenXRLoader.build.cs should be part of all InstalledBuild

Tech - BuildOps - Infra - Oct 2, 2025

The OculusOpenXRLoader module is only required on Android but it should be possible to reference it from any project\plugin that doesn't target that platform.  The user that found the problem is ...

Recompiling an ABP that another ABP has a Property Access dependency on without recompiling/linking the other causes a crash

UE - Anim - Runtime - Anim Blueprints - Oct 2, 2025

The crash comes from the pointers in FAnimSubsystem_PropertyAccess::Library::Indirections in the layer ABP from pointing to old/invalid functions and properties from the trash ABP_Manny, as they hav ...

Skeleton retarget settings are lost when importing/reimporting a mesh with bone hierarchy changes

UE - Editor - Content Pipeline - Import and Export - Sep 30, 2025

Importing a mesh that changes the hierarchy of a related skeleton causes the animation retarget settings on the skeleton to be lost. This is because in UInterchangeSkeletalMeshFactory::EndImportAss ...

Wrong density calculation in UBodySetup::CalculateMass

UE - Simulation - Core - Sep 29, 2025

Wrong density calculation in UBodySetup::CalculateMass. The licensee has provided the following analysis and suggested fix: In UBodySetup::CalculateMass, the following code is present: // physical ...

[Mobile/Forward Rendering] PlanarReflection does not work when the reflection plane faces certain directions

UE - Platform - Mobile - Sep 24, 2025

Note: This repros on 4.27 and all 5.x versions. When using the mobile renderer and/or forward shading, Planar Reflection will simply not work if the reflection plane normal has components that add ...

Iris - actors spawned/loaded before a connection exists will not use delta compression

UE - Networking - Iris - Sep 24, 2025

FDeltaCompressionBaselineManager::CreateBaseline will return early if the object has an invalid ObjectInfoIndex, which is allocated in FDeltaCompressionBaselineManager::UpdateScope (by calling FDelt ...

FBlackboardKeySelector filters aren't applied when recompiling blueprint if a behavior tree asset containing the blueprint added as a service is closed, or if the blueprint is reparented.

UE - AI - BehaviorTree - Sep 24, 2025

Context In Behavior Trees, BT Services can be added to nodes. Those services can have configurable FBlackboardKeySelectors. BlackboardKeys are variables on a blackboard that the behavior tree can r ...

Post Process Animation Blueprint Crash When Using Blend Node

UE - Anim - Runtime - Anim Blueprints - Sep 24, 2025

When using a Blend node inside a Post Process Animation Blueprint, the editor crashes while rendering thumbnails. The crash occurs because USkeletonThumbnailRenderer attempts to draw a thumbnail wit ...