Base materials in exported Datasmith files imported into Unreal Engine are missing material function.

TM - Interoperability - Nov 19, 2024

Datasmith imports in UE do not render materials due to missing material function. Works in UE 5.6 main but not UE 5.5 or 5.4 ...

Nanite TwoSidedSign is backwards

UE - Rendering - Features - Nanite - Apr 10, 2025

The value of MaterialExpressionTwoSidedSign is flipped when calculating the Opacity Mask for Nanite meshes. This seems to be a regression in 5.5. ...

Landscape has a seam when scale is set to a decimal

UE - Graphics Tools - Terrain - Landscape - Jan 13, 2023

Regression: Tested in UE5/Release-5.0 at CL 20979098, this issue does occur so it is not a regression. This issue occurs if the scale set for the landscape has a decimal value that is not 0.5. Sett ...

Root Motion Not Retained when Retargeting Animation Assets from UE4 to UE5

UE - ACT Character - Retargeting - Apr 12, 2022

Occurs 5/5 Times RootMotion of an animation asset is not retained when retargeting Root Motion Animation asset from UE4 to UE5.  ...

Adding Megascans 3D objects to a scene can cause Twinmotion to freeze and Crash on macOS.

TM - Core - Dec 11, 2024

Looking at the logs when it happened, the logs are spammed with the following: [2024.12.10-20.34.12:438][514]LogZenServiceInstance: Display: Unreal Zen Storage Server HTTP service at [::1]:8658 sta ...

Crash when Undo after deleting a Material Layer of a Material Instance.

UE - Rendering - Architecture - Materials - Apr 2, 2025

In Unreal Engine version 5.5.4, the Editor crashes when performing Undo after deleting a Material Layer of a Material Instance ...

Moving folder of assets crashes editor

UE - Simulation - Physics - Dec 23, 2015

Moving the contents folder for the Dynamic Clocks marketplace asset crashes the editor immediately. Frequency: 5/5 CrashReporter: [Link Removed] ...

Collision profiles are reset when blueprint is loaded

UE - Gameplay - Jan 6, 2025

In UE 5.5 (and earlier versions), FCollisionResponse::operator== has incorrect behavior where it will detect that two collision response containers are identical if they have the same number of entr ...

WorldToClip/ClipToWorld transform in materials not behaving as expected

UE - Rendering - Features - Dec 19, 2025

In 5.3, the specified code will return all 0 or very small as expected. However in 5.4.4 and onwards (also checked in 5.6.1 & 5.7.1), it returns very large numbers. ...