Unreal Engine Issues
Unreal Engine Issues
Long thin spinning objects take too long to stop spinning
UE - Simulation - Core - Jun 5, 2023See the SpinningObjectStability test map in the Physics Sandbox. [Link Removed] It's not clear if this is a bug or a side effect of some of our solver shortcuts (e.g., omission of the precession te ...
AreaNavModifiers generated by SplineNavModifierComponent have the component-to-world transform incorrectly applied twice
UE - AI - Navigation - Aug 15, 2025USplineNavModifierComponent was made available in UE 5.4. It generates several FAreaNavModifier instances covering a region with a certain thickness around a USplineComponent, and worked correctly u ...
FBX animations generated under fractional framerates fail to import
UE - Anim - Runtime - Aug 24, 2022We 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, 2024When 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, 2025Slack: [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, 2025The 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, 2022Reproduced 3/3 times, issue also occurs in //UE5/Release-5.0 - CL 20979098 Binary. Confirmed NOT a Regression. ...
Getting Fullscreen or Windowed Resolutions doesn't fully execute on Linux
UE - Rendering Architecture - RHI - Oct 28, 2019When using "Get Supported Fullscreen Resolutions" on UE when built with Vulkan, no values are printed out. This is an issue with any platform that builds UE with -vulkan, not just Linux. In Engine ...
Spline mesh crashing in FRayTracingDynamicGeometryCollection::AddDynamicMeshBatchForGeometryUpdate
UE - Graphics Features - Ray Tracing - Jan 31, 2025A 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, 2025When 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, ...