Crash when clicking "Reset to Default" button on the Details Panel for the MaterialAttributeLayers material node.

UE - Rendering Architecture - Materials - Jul 15, 2025

This crash repros from at least UE 5.3 and up to latest. The following assert is hit: Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 1067] Array index out of bounds: 0 in ...

Conflict between sequencer transform track and Parent Constraint from the Animation Mode breaks temporary pivot translation on any actor

UE - Anim - Anim in Engine - Jul 15, 2025

Note: This affects all versions from at least UE 5.3, including mainline latest. The "Animation" Editor Mode allows creating constraints for level actors. One of these, the "Parent" constraint, con ...

When moving actors to the current level, their label is reset and displayed incorrectly on the Scene Outliner until the next time it is refreshed

UE - Editor - Workflow Systems - Jul 14, 2025

This is a regression, it worked correctly up to UE 5.4, but repros on UE 5.5 and 5.6. Also, this seems related to [Link Removed], which was fixed by CL 40649716/40649749 and integrated into UE 5.6, ...

Channel Mask Parameter does not correctly pull through the Alpha channel from

UE - Rendering Architecture - Materials - Jul 8, 2025

The ChannelMaskParameter node in the Material Graph works in most cases, but unusually does not work when extracting the value of the Alpha channel only for Vertex Color input data. ...

Sequencer - When a subsection has negative play rate, any nested sub-subsections fail to evaluate

UE - Anim - Sequencer - Jul 3, 2025

Consider a sequence hierarchy with more than two layers. If the top-level sequence uses a negative timescale on a sub-sequence, the contents inside it animate as expected, but any nested sub-sequenc ...

CPU Lightmass generates different lighting results on a landscape if executed via a commandlet vs through the editor

UE - Graphics Features - Jul 3, 2025

Building lighting via commandlet and via editor are giving different results. To prevent one method from polluting the other via Swarm cache, the cache needs to be cleared in between tests. ...

Inconsistent Details Panel Focus Behavior On Enter Pressed for Blueprint-Added Components

UE - Editor - Workflow Systems - Jul 2, 2025

When editing a component property in the level viewport, if the component was added via the Blueprint Editor, pressing Enter after changing a value causes the details panel to lose focus. This inter ...

Incorrect UV coordinates when visualizing mesh painting texutre on Nanite splines

UE - Graphics Features - Jun 30, 2025

The UV coordinates for visualizing the mesh painting texture on Nanite spline meshes are not working correctly. This runs the code in the NANITE_VISUALIZE_MESH_PAINT_TEXTURE section in NaniteVisuali ...

Unwanted offset on curves when importing animation assets

UE - Editor - Content Pipeline - FBX - Jun 27, 2025

Hello, We seem to have encountered some unwanted behaviour when importing certain curves from our animation fbx assets into Unreal. Some of these curves don't have keys from the very first frame, b ...

Sphere Mask ArgInvHardness missing multiplication

UE - Rendering Architecture - Materials - Jun 27, 2025

Hi Epic, In MaterialExpressions.cpp UMaterialExpressionSphereMask::Compile(), hardness is not calculated the same way in both <if> conditions. One is missing a multiplication by 0.01f. Specificall ...