Nanite Displacement Bounds Mismatch Causes Floating Terrain Artifacts on Landscape

UE - Rendering - Graphics Features - Nanite - Mar 19, 2026

Summary When Nanite Tessellation (Nanite Displacement) is enabled on a Landscape in UE 5.7.3, scaling the Displacement value via Multiply nodes in the material graph causes floating terrain ghost a ...

When CommonTabListWidgetBase and ScrollBox are arranged vertically, tabs within CommonTabListWidgetBase momentarily become selected when scrolling the ScrollBox upward

UE - Editor - UI Systems - UMG - Mar 19, 2026

When attempting to scroll the ScrollBox upward, the cursor briefly shifts focus to another widget (CommonTabListWidgetBase). When logging this behavior using LogSlate VeryVerbose, it can be observed ...

Substrate Unlit editor view mode renders black with Blendable GBuffer

UE - Rendering - Graphics Features - Substrate - Mar 18, 2026

When using Substrate materials with SUBSTRATE_GBUFFER_FORMAT==0 (Blendable GBuffer), the Unlit editor view mode renders completely black. TopLayerData.UnlitViewBaseColor is never populated in the bl ...

JsonObjectToUStruct removes _ClassName from input FJsonObject, breaking repeated deserialization

UE - Foundation - Mar 18, 2026

FJsonObjectConverter::JsonObjectToUStruct removes _ClassName from nested JSON objects during deserialization. Removing Obj->RemoveField(ObjectClassNameKey) from ConvertScalarJsonValueToFPropertyWit ...

Control Rig Physics world collision fails against ISM component meshes

UE - Anim - Synthesis - Physics Control - Mar 17, 2026

CRP currently fails to collide against the bodies generated by ISM components. This is because the collision body data is stored in a different property for ISMs vs regular primitive components. ...

Skeletal Mesh Cloth - Removing cloth collision sources doesn't remove the prerequisite, and the collision sources are not updated

UE - Simulation - Visual - Mar 17, 2026

[Link Removed] See proposed fix from partner: [Image Removed] ...

Modular rig - Hindleg thigh bug when switching from IK to FK

UE - Anim - Rigging - Control Rig - Mar 16, 2026

The thigh FK controller of the hingleg in modular rig doesn't move the thigh bone, causing bad deformation on the mesh around character's thigh area. ...

Dangling pointer + mem corruption related to OwnerLastRenderTimePtr

UE - World Creation - Worldbuilding Tools - Mar 16, 2026

We've been seeing asserts and crashes related to OwnerLastRenderTimePtr. We've traced this to the mentioned pointer ending up dangling after using UActorComponent::Rename() on primitive components t ...

Cursor radius set via FSlateApplication::SetCursorRadius is ignored during FHittestGrid hit testing

UE - Editor - UI Systems - Slate - Mar 16, 2026

The cursor radius configured through FSlateApplication::SetCursorRadius() is not respected during Slate hit testing. The radius value is correctly stored in FSlateApplication and passed into FHittes ...

AnimNode content is not applied during PIE when s.AsyncLoadingThreadEnabled is enabled

UE - Anim - Runtime - Anim Blueprints - Mar 16, 2026

When the following setting is added to DefaultEngine.ini, the AnimNode content is not applied during PIE execution.[/Script/Engine.EditorStreamingSettings] s.AsyncLoadingThreadEnabled=True If the A ...