FName no longer equals FName_None when constructed with a trailing underscore and digits in range of 1-9

UE - CoreTech - Apr 15, 2025

When an FName is created with a trailing underscore and any number of digits in the range of 1-9 the trailing digits are used as the internal number value for the FName lookup. This results in the F ...

Inconsistent parameter handling for pak/iostore block size / patch padding

UE - CoreTech - IoStore - Apr 14, 2025

Users have trouble overriding the blocksize/patchpaddingalign parameters for UnrealPak from UAT commandlines.There is no easy way to specify these parameters through a buildcookrun, instead they n ...

Crash in GPUMessage.cpp when resetting FSocket when RHI is NullRHI.

UE - Rendering - Architecture - RHI - Apr 5, 2025

When tearing down a nanite project with the nullrhi active, there is a crash in the FeedbackManager destructor that causes any exit to be unclean. The teardown process causes a crash as the destruc ...

Non-Nanite Instanced Static Mesh Collision not showing in collision view

UE - Simulation - Core - Apr 3, 2025

This issue is the same as [Link Removed] Closed , but it causes confusion for developers because only Nanite ISM are rendere ...

UAT not considering remote root

UE - Foundation - Horde - BuildGraph - Apr 2, 2025

It seems like WriteFileList (TempStorage.cs) is not respecting the enginePath as set from horde context. _localDir in TempStorage.cs seems to be based off of the RootDir (details here). Proposed ...

Skylighting on distant objects causes severe flickering with Lumen

UE - Rendering - Graphics Features - Lumen - Mar 31, 2025

Lighting on distant meshes flickers when using Lumen and Skylights. Turning Lumen off and lighting from the skylight is stable. Turning off Lumen screen traces also lowers the amount of flickering ...

Opcode shader compilation error when using a TextureSampleParameterCubeArray node with hardware ray tracing enabled

UE - Rendering - Graphics Features - Ray Tracing - Mar 31, 2025

Materials containing a cube array texture sampling node will not compile when hardware ray tracing is enabled. The shader compilation error indicates that an invalid op code was used: "Opcode Sample ...

UAnimNotify::Notify not called during USkeletalMeshComponent interaction with UPhysicsControlComponent when PhysicsBlendWeight is zero

UE - Anim - Synthesis - Physics Control - Mar 30, 2025

UAnimNotify::Notify not called during USkeletalMeshComponent interaction with UPhysicsControlComponent when PhysicsBlendWeight is zero. The licensee has provided his analysis of the code: If USkelet ...