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

UE - AI - 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 ...

Tooltips not appearing in Editor when hovering over assets due to Slate Cursor Move settings

UE - Editor - UI Systems - Slate - Feb 3, 2026

User noticed that when Slate.EnableSyntheticCursorMoves is set to false the editor UI tooltips no longer display. As noted by the user, modifying Slate.CursorSignificantMoveDetectionThreshold to at ...

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 ...

Material Functions are incorrectly listed in the Layer Asset list

UE - Rendering Architecture - Materials - Feb 3, 2026

Since UE 5.7, Material Functions are included in the Layer Asset list of the Material Layers of an instanced material using material layers. It is also possible to drag and drop Material Functions ...

UMovieSceneAudioSection delegates do not get bound to recycled audio components

UE - Anim - Sequencer - Feb 2, 2026

When audio sections have delegates bound to things like SetOnAudioFinished and that audio section ends up being played through a recycled audio component inside UMovieSceneAudioSystem, the delegates ...

MRQ reports missing frames when rendering multiple cameras on a Sequencer camera track with Temporal Sample Count > 1

UE - Virtual Production - Tools - MRQ - Feb 2, 2026

If there are multiple cameras in the Sequencer camera track, everything works correctly when the Temporal Sample Count for anti-aliasing is set to 1. However, when it is set to 3, the following erro ...

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 ...

Compatible Skeleton Animation does not retarget the same on duplicate skeleton

UE - Anim - Rigging - Retargeting - Jan 29, 2026

If a mesh is exported from the engine, reimported as a new skeleton and mesh, and then marked as a compatible skeleton. Animation will have slightly different rotations playing on the skeleton. ...

Crash when enabling Nanite on a Mesh using an OptimusDeformer

UE - Anim - Rigging - Deformer - Jan 29, 2026

When a skeletal mesh has a deformer present and then nanite support is enabled and applied. (the deformer in question was hsasset://DeformerGraph/Deformers/DG_LinearBlendSkin_Morph_Cloth_RecomputeNo ...

Incorrect geometry for OnMouseMove event on Slider with RightToLeft flow direction

UE - Editor - UI Systems - Slate - Jan 28, 2026

When a slider is in RTL flow direction, and thus its position is changed, the handle is not drawn at the correct position during mouse drag. Instead, the handle draws as if the slider was not moved ...