FBX animations generated under fractional framerates fail to import

UE - Anim - Runtime - Aug 24, 2022

We now have the following error that is generated in FFbxImporter::ValidateAnimStackif (!FMath::IsNearlyZero(SubFrame, KINDA_SMALL_NUMBER) && !FMath::IsNearlyEqual(SubFrame, 1.0f, KINDA_SMALL_NUMBER ...

Pasting custom data floats from a text editor into a instanced static mesh component crashes the editor

UE - Framework - Components - Aug 5, 2024

When an instanced static mesh component with a material using a PerInstanceCustomData node has its data floats pasted in, the editor crashes with an "Array index out of bounds" error. The licensee w ...

Illegal reference to private object when cooking a child level sequence with a time warp track

UE - Anim - Sequencer - Apr 28, 2025

Slack: [Link Removed] Cook error: UATHelper: Cooking (Windows): LogSavePackage: Warning: UATHelper: Cooking (Windows): Referencers of MovieSceneTimeWarpSection /Game/ChildSequence.ChildSequence: ...

Disabling bLerpUVs in Nanite Settings of Static Mesh causes texture warping in clusters

UE - Graphics Features - Nanite - Jan 21, 2025

The licensee has identified a potential fix by changing if( Settings.bLerpUVs ) to if( Settings.bLerpUVs || UVIndex == 0 ) On line 389 of NaniteBuilder\Private\Cluster.cpp in UE 5.5 ...

Get Material Instance ___ Parameter Value not working for Blend Parameter

UE - Rendering Architecture - Materials - Dec 2, 2022

Reproduced 3/3 times, issue also occurs in //UE5/Release-5.0 - CL 20979098 Binary. Confirmed NOT a Regression. ...

Spline mesh crashing in FRayTracingDynamicGeometryCollection::AddDynamicMeshBatchForGeometryUpdate

UE - Graphics Features - Ray Tracing - Jan 31, 2025

A crash occurs when using ray tracing with spline meshes preceded by the following ensure : Ensure condition failed: NumCPUVertices <= VertexBufferNumElements  File: Engine\Source\Runtime\Renderer\ ...

Incorrect mesh deformation when Max World Position Offset Displacement used

UE - Graphics Features - Nanite - Feb 12, 2025

When Vertex Animated Texture is used to animate a mesh with World Position Offset, often the Max World Position Offset Displacement Material setting must be increased or the Bounds Scale increased, ...

Anisotropy renders differently in each eye in VR

UE - Platform - XR - Jan 10, 2023

Regression: Tested in Release-5.0, this issue occurs so it is not a regression. This issue was first reported using the Automotive Materials assets, as the Anisotropy material on MI_Metal_Brushed w ...

Buoyancy is broken in UE5: even BP with Cube SM component (mass is 1kg) and default Buoyancy Component with one default Pontoon falls on bottom of lake

UE - Simulation - Visual - Jul 26, 2021

Shorter steps:Steps 1-8 from Steps to reproduce (create level with water body)Find BP_BuoyancyExample in Content Browser (Engine>Plugins>Water Content>Blueprints)Place BP_BuoyancyExample above the w ...

StopMontage with different BlendOutTime not taken into account after first StopMontage

UE - Anim - Gameplay - Nov 19, 2024

When an animation is currently blending out due to automatic blend out or GameplayLogic, further StopMontage with specific BlendOut will not update the time to blend out of the current blending out ...