Ending a GameplayAbility from an AbilityTask created by the same GameplayAbility does not correctly end the AbilityTask, and it continues ticking.

UE - Gameplay - Gameplay Ability System - Feb 2, 2026

When a GameplayAbility is ended from within a child AbilityTask, the AbilityTask is not cleaned up correctly. As a result, even though the GameplayAbility is no longer active, the AbilityTask contin ...

Crash when enabling Nanite on a Mesh using an OptimusDeformer

UE - Runtime - Deformable - Jan 29, 2026

When a skeletal mesh has a deformer present and then nanite support is enabled and applied. (the deformer in question was hsasset://DeformerGraph/Deformers/DG_LinearBlendSkin_Morph_Cloth_RecomputeNo ...

PCG Volume does not regenerate after being moved through a sequencer sequence

UE - Graphics Tools - PCG - Components - Jan 23, 2026

Any transform modifications on the PCGVolume by Sequencer use USceneComponent::SetRelativeTransform directly and are not tracked by the TrackingManager (FPCGTrackingManager::OnObjectPropertyChanged ...

Custom Primitive Data is not affected in the skeletal mesh on BP instances in the editor

UE - Rendering - Architecture - Jan 22, 2026

Editing Custom Primitive Data values ​​in the details panel of a placed BP actor with a Skeletal Mesh component does not reflect in the Editor viewport. ...

Changing the ComponentClass of a ACharacter twice and trying to set a SkeletalMeshAsset crashes the engine

UE - Runtime - Animation - Jan 22, 2026

Changing the ComponentClass of a ACharacter twice and trying to set a SkeletalMeshAsset crashes the engine with a "Cannot replace existing object of a different class" message. The conditions to re ...

Character unnecessary step down during PHYS_Flying mode

UE - Runtime - Character - Jan 15, 2026

When MovementMode is set to PHYS_Flying, the character may unexpectedly step down by MaxStepHeight when colliding with a wall near a ceiling. This occurs because UCharacterMovementComponent::StepUp ...

Temporal blur artifacts on Geometry Cache Components in Blueprint actor

UE - Editor - Content Pipeline - Alembic - Jan 9, 2026

When a Geometry Collection is in a Blueprint, attached to other components, it can render incorrect motion vectors at some angles. In the test project, any angle that is not a multiple of 45 will re ...

Inconsistent Behavior in TextureLODGroups when setting NumStreamedMips=0

UE - Rendering - Architecture - Jan 8, 2026

A licensee has reported that it is not possible to disable texture streaming of a given TextureLODGroup by setting "NumStreamedMips=0" in their device profiles. Currently, using 0 results in the sam ...