Morph target normals not correctly applied when imported as LOD 0

UE - Editor - Content Pipeline - FBX - Nov 27, 2025

This is a regression since 5.5 with skeletal meshes where morph target normal/tangent deformation only works when a mesh is imported as a LOD of an existing skeletal mesh, but not when imported as L ...

Crash Duplicating an empty AtlasRow material node

UE - Rendering Architecture - Materials - Nov 29, 2023

This isn't a hard crash, but a "verify(...)" from MaterialExpressions.cpp, line 559. ...

Deadlock in UAnimationSequencerDataModel::Evaluate where FScopeLock Lock(&EvaluationLock) blocks execution indefinitely

UE - Anim - Nov 4, 2025

When both the Sequencer Editor and an Animation Curve Editor are open for the same animation asset, the editor freezes completely upon editing the curve. Analysis indicates that the freeze is caus ...

[Review Tool] The editor crashes while attempting to load a modified Blueprint that uses Interface for review.

The crash is due to previous Rename operation, that reset a preallocated array which later FAsyncPackage2::ExecuteDeferredPostLoadLinkerLoadPackageExports tries to use.  Before loading change list ...

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 ...

CreateD3D12Texture causes the Low Level Memory system to register two allocations for the same pointer on the same track channel

UE - Rendering Architecture - RHI - Oct 31, 2024

CreateD3D12Texture causes two OnLowLevelAllocs in LLM to be called with the same pointer and the same channel, leading to a warning. LLM WARNING: Replacing allocation in tracking map. Alloc/Free Mi ...

Reset to default behavior for arrays is inconsistent about updating customized struct headers

UE - Editor - Workflow Systems - Jun 22, 2023

The behavior for resetting the default for customized struct properties is inconsistent and needs to be reviewed and fixed. Currently we see this behavior:In non-array properties, the header will be ...

Demo Record does not play back the events that occurred after the ServerTravel command.

UE - Networking - Sep 16, 2021

Regression was checked on UE5-Release-EarlyAccess CL 16682836, Regression - No. ...

ChaosWheeledVehicleMovementComponent is breaking the const CDO contract and changes to the instances are being applied to the CDO

UE - Simulation - Gameplay - Apr 28, 2025

As described by the licensee, the const CDO contract is being broken on ChaosWheeledVehicleMovementComponent. The issue the licensee is facing is that by spawning cars with different configurations, ...

ResavePackages commandlet (buildlighting) fails/asserts on reflection captures in non-visible sub-levels

UE - Graphics Features - May 13, 2025

When building reflection captures through the ResavePackages commandlet, it frequently triggers an ensure inside of ReflectionEnvironmentCapture.cpp. If distributed shader builds start causing prob ...