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 ...

Section::TrimSection resulting in bad key values at start and end of trim range

UE - Anim - Sequencer - Dec 17, 2025

The trim process inserts keys at the start or end of the range depending if you specify Trim Left or Right, I'm finding that Trim right is inserting a key at the end of the section that is incorrect ...

ActorComponents registered with wrong world from UWorldPartition::ApplyRuntimeCellsTransformerStack

UE - World Creation - Worldbuilding Tools - World Partition - Dec 17, 2025

There is a risk of actor components registering with the wrong world when reconstructed from UWorldPartition::ApplyRuntimeCellsTransformerStack. The repro case is arguably a bad usage, but it was th ...

A chaos vehicle that moves at very high speeds with CCD enabled on the vehicle sometimes has a collision response that is abnormal where the vehicle loses a significant amount of speed when colliding with dynamic objects configured as One Way Interaction

UE - Simulation - Gameplay - Dec 16, 2025

Context: Continuous Collision Detection (CCD) is being used on a Chaos Vehicle to avoid tunneling issues with certain surfaces as it prevents any missed collisions between fast moving particles and ...

[AI] StateTree fails to compile after copy/pasting a state with a task that binds to required event on the state's enter conditions

UE - AI - StateTree - Dec 14, 2025

StateTree appears to keep an incorrect reference to the event from the source tree rather than re-establishing the property binding to the new tree's event. This happens when copy/paste of the state ...

VirtualTextureStreamingPriority cannot be set per TextureLODGroup

UE - Rendering Architecture - Dec 11, 2025

It is currently not possible to set a VirtualTextureStreamingPriority via the TextureLodGroups that are defined in a device profile. ...

[ALT] - UE56 Editor launched with -AsyncLoadingThread will trigger MTAccess

UE - Foundation - Core Systems - EditorLoader - Dec 10, 2025

When launching the editor with the -AsyncLoadingThread command, the engine uses an asynchronous thread to load and instantiate UObjects. At this point, if the instantiated UObject contains an FData ...

Convex hull generation fails when first 3 verts are colinear

UE - Simulation - Core - Dec 9, 2025

The licensee identified a number of cases where loading assets will trigger convex hull generation warnings:If the first 3 verts in the set are colinear (in which case IsPlanarShape() returns true b ...

Texture Streaming can randomly streams in all Mips, causing large memory spikes

UE - Rendering Architecture - RHI - Dec 5, 2025

A possible race condition allows texture instance views to read uninitialized bounds, causing either garbage or zero screen size values to be returned by FRenderAssetInstanceAsyncView::GetRenderAsse ...

Drag and Drop fails in Standalone and Packaged builds when WidgetComponent’s Widget is set at runtime

UE - Editor - UI Systems - Dec 4, 2025

When a UWidgetComponent has its widget assigned dynamically at runtime using CreateWidget and SetWidget, drag & drop operations fail in Standalone Game and packaged/game builds, while working correc ...