Editor localization causes the GetLinkedAnimLayerInstanceByGroup function to fail in retrieving the corresponding LinkedAnimLayer within the editor.

UE - Anim - Runtime - Anim Blueprints - Dec 18, 2025

When using other language(such as Chinese) as editor language, the Group Name of the Animation Interface will be localized to Chinese. In editor, the animation blueprint grab the group from metadata ...

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 ...

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 - DEET - 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 ...

Issue with Niagara emitter inheritance

UE - Niagara - Dec 4, 2025

Modules in the particle spawn stage get unlocked and lose inheritance after changing the inherited emitter's interpolated spawn mode to "No Interpolation" then resetting. ...

Morph target is not applied on the first frame in Level Sequence

UE - Anim - Rigging - Dec 4, 2025

When a skeletal mesh with morph targets spawns in the sequence, the morph is not reflected in the first frame.  In the ProcessStage_SkinCache call of SkeletalMesh, MorphVertexBuffer->SectionIds is ...