Division by zero causing NaN/Inf on USkeletalMeshComponent::UpdateRigidBodyScaling() when setting scale to zero and back

UE - Runtime - Simulation - Feb 11, 2026

Up to UE 5.5, skeletal mesh physics did not get updated when the component's scale changed. This was improved on January 2025 with CL 39190335, which addressed [Link Removed] ...

Enum Compare Condition causes crash when resetting default value of right field in State Tree's Enter Conditions

UE - AI - StateTree - Feb 11, 2026

In FStateTreeCompareEnumCondition::GetDescription, the Left.Enum value is mistakingly used when setting the RightValue. This causes crashes when resetting the default value of the Right field in an ...

StaticMesh reimport not preserving support for physical material masks

UE - Runtime - Simulation - Feb 10, 2026

Client has a workflow issue with the reimport pipeline: UStaticMesh::bSupportPhysicalMaterialMasks should be copied over to UBodySetup::bSupportUVsAndFaceRemap before it takes effect for raycasts, ...

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 ...

Chaos Cloth - Multiple issues with convex colliders

UE - Runtime - Deformable - Feb 6, 2026

Issue 1: Convex Collision Transformation Missing for External Collision Sources Issue 2: Convex CCD Stability Issues due to Plane Intersection Semantics See attached URL for more details. ...

DynamicMaterialParameters Niagara module resets write flags on emitter update

UE - Rendering - Architecture - Niagara - Feb 4, 2026

When using the DynamicMaterialParameters Niagara module in UE 5.6, 5.7, and UE5-Main (CL 50298778), updating an emitter causes Boolean values, such as Index0Float0Write, to reset to default values, ...

Mass entities initializing fragments on the incorrect archetypes due to shared CreationContext

UE - Engine Scaling - Mass - Feb 3, 2026

UMassAgentSubsystem::HandlePendingInitialization creates a single FEntityCreationContext that is reused across all iterations of the PendingAgentEntities loop. When SpawnEntities eventually calls in ...

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 ...

“S” key fails to add key to transform when additive track Is locked

zComponent - Archive - Feb 2, 2026

When an additive transform track is locked, pressing the “S” key does not add a new key to the sequence. No key is added to either the additive track or the base transform track. What the user expe ...

Enabling MobileHDR on Meta Quest 3 device causes intermittent hang in splash screen

UE - Platform - XR - Feb 2, 2026

Using MobileHDR on an actual MetaQuest device (MQ3 tested) causes an intermittent hang/deadlock in the splash screen. This hang in the splash screen seem to happen maybe 1 in 5 times. The first ti ...