FViewElementPDI::DrawLine calls for SDPG_World are not rendered in PIE or in Game

UE - Rendering - Architecture - RHI - Jan 7, 2026

When View.Family->EngineShowFlags.CompositeEditorPrimitives is false in the function RenderEditorPrimitivesForDPG. This code picks which version of the batched lines to renderconst FBatchedElements ...

CommonListView EntryWidgetClass allows invalid assignment via “Use Selected Asset From Content Browser”

UE - Editor - UI Systems - Jan 6, 2026

CommonListView requires its EntryWidgetClass to implement UserObjectListEntry. This requirement is correctly enforced by the Entry Widget Class dropdown, which filters out widgets that only implemen ...

Skeletal Mesh BLAS updates when not animating

UE - Rendering - Architecture - RHI - Dec 19, 2025

The BLAS for Skeletal Meshes that don't move, or tick get updated every frame even if the animation and skin cache aren't updated. This adds over 1ms to update time. The only exception is if the sk ...

Subobject ComponentClass overrides cause failing assertions due to UObject reconstruction on AsyncLoadingThread

UE - Engine Scaling - dSTM - Dec 19, 2025

Context The blueprint editor allows you to override an actor component's class in derived blueprints (component details panel -> Component Class). [Image Removed] Problem When a blueprint and it ...

Actor Components incorrectly appearing mixed with the Scene Component Hierarchy in the Component Tab of the Blueprint Editor

UE - Framework - Blueprint Editor - Dec 19, 2025

This is a regression introduced by CL 45871568 in ue5-main branch. The new function FFBlueprintEditorDefaultSortUICustomization::SortSubobjectData() in file "BlueprintEditorSCSEditorUICustomization. ...

Reflections of Masked Materials incorrect with Lumen HWRT and Max Refraction Bounces > 0

UE - Rendering - Graphics Features - Lumen - Dec 18, 2025

Lumen HWRT Reflections of Masked Materials are incorrect when "r.Lumen.Reflections.HardwareRayTracing.Translucent.MaxRefractionBounces" is greater than 0. The same issue occurs if the Post-Process V ...

Changing bIsSpatiallyLoaded can cause an Actor to be duplicated during Play-In-Editor

UE - World Creation - Worldbuilding Tools - World Partition - Dec 18, 2025

Changing bIsSpatiallyLoaded can cause an Actor to be duplicated during Play-In-Editor. As described in the steps to reproduce, if we keep swapping bIsSpatiallyLoaded state and save a Streaming Level ...

Cooker is asserting in Class.h on UE 5.7.1

UE - CoreTech - Dec 18, 2025

From the linked EPS case: ---------------------------- In UE 5.7 there were some changes to how Enum member names are stored. This change introduces an assert when cooking using the Editor Debug e ...

If a child blueprint class has an Instanced/EditInlineNew object property, that property will always be detected as changed by the property editor (i.e. it will show a "Revert" arrow on that property), even if its properties are identical to the parent.

UE - Framework - Blueprint Editor - Dec 17, 2025

Context: Blueprint classes can use Instanced/EditInlineNew object property specifiers to create and edit subobjects directly in the editor. Problem: If a child blueprint class has an Instanced/Edit ...

Viewport stuttering during orbit/zoom navigation

UE - Rendering - Graphics Features - Dec 17, 2025

Received a report of persistent stutters in the editor when trying to navigate in the viewport, including asset editor viewports like the Skeletal mesh editor and control rig editor. Hardware used ...