Crash when calling FillDataTableFromCSVString() while viewing the contents of the data table

When the function UDataTableFunctionLibrary::FillDataTableFromCSVString() is used from Editor Utility Blueprints or Python Scripts, and the contents of the affected Data Table are currently being vi ...

IKRetargeting Skeletal Mesh Does Not Update Virtual Bones

zComponent - Archive - May 20, 2022

Occurs 5/5 times. Regression does not occur: UE5Manny Skeletons are new to UE5.0  ...

Nanite Displacement Bounds Mismatch Causes Floating Terrain Artifacts on Landscape

UE - Rendering - Graphics Features - Nanite - Mar 19, 2026

Summary When Nanite Tessellation (Nanite Displacement) is enabled on a Landscape in UE 5.7.3, scaling the Displacement value via Multiply nodes in the material graph causes floating terrain ghost a ...

WorldPartitionConvertCommandlet hits an assert when converting a persistent level that contains a sub-level with a landscape

UE - World Creation - Worldbuilding Tools - Nov 7, 2025

Context: The Window tab allows a user to open the Levels window in order to add a sub-level to a persistent level. For Unreal Engine 5.0 and beyond, World Partition has made the Levels window obsole ...

UNetDriver server-side hitch results in ActorInfo->NextUpdateTime far into future

UE - Networking - Feb 16, 2024

A high UWorld::Tick DeltaSeconds (i.e. GameThread hitch) results in a high UNetDriver::TickFlush DeltaSeconds. This DeltaSeconds can high (many seconds) if the hitch is long. This value then affects ...

Niagara - When Interpolated Spawning is disabled, the first frame of each particle unexpectedly does not take into account the Particle Update stage

UE - Niagara - Feb 28, 2025

Foreword: Even if the behavior described here is by design, it is rarely (if ever) expected or desired. This was discussed and agreed to be treated as a bug. Explanation below. When interpolated sp ...

Chaos Fields: LS_MasterField continuously creates components every frame and never cleans them up

UE - Runtime - Deformable - Mar 25, 2026

While active and ticking, the built-in FS_MasterField actor instance continuously creates several new components every frame, which are never cleaned up until the actor is destroyed. This can happen ...

Velocity Scene Texture Data Integrity Issues

UE - Graphics Features - Jan 8, 2026

When a Post-Process Material uses the Scene Texture Material Expression, the following code is generated: ``` MaterialFloat2 Local0 = Parameters.TexCoords[0].xy; MaterialFloat2 Local1 = ClampSceneT ...

Blueprint with Niagara System and Skeletal Mesh Components Automatically Updates Niagara System Skeletal Mesh

UE - Niagara - Apr 4, 2019

When adding a niagara system that reproduces a skeletal mesh and a skeletal mesh as components to a blueprint, the niagara system immediately updates its skeletal mesh to the most recently updated s ...

Crash when removing and re-adding instances to an InstancedStaticMeshComponent with PerInstanceCustomData.

UE - World Creation - Worldbuilding Tools - Jan 22, 2026

When using an InstancedStaticMeshComponent with PerInstanceCustomData, the number of float elements in the "Custom Data" array should always be equal to NumCustomDataFloats multiplied by the number ...