ensure(false) being fired in FGenericParticlePairMidPhase::FindOrCreateConstraint from key collision

UE - Simulation - Physics - Jan 27, 2025

ensure(false) being fired in FGenericParticlePairMidPhase::FindOrCreateConstraint from key collision. The licensee reports one of their users reported this issue and they were able to reproduce a fe ...

Duplicating many Actors at once in a Level Instance while in Level Instance Edit will result in a jumbled mess of Actors on the Persistent Level

UE - World Creation - Worldbuilding Tools - Level Instances - Feb 12, 2025

Duplicating many Actors at once in a Level Instance while in Level Instance Edit will result in a jumbled mess of Actors on the Persistent Level. The licensee has encountered this in Unreal 5.4 and ...

Pressing Cancel after ColorPicking a Sequencer's tracked Color will not reverted the color to the previous value

UE - Anim - Sequencer - Jun 22, 2025

Pressing Cancel after ColorPicking a Sequencer's tracked Color will not reverted the color to the previous value. There's a bug when ColorPicking a color that is being tracked in Sequencer - pressin ...

Undoing keyframe addition in Sequencer unselects actors in the Outliner

UE - Anim - Sequencer - Sep 8, 2025

When a keyframe is added to a track in the Sequencer, undoing the operation correctly removes the keyframe, but it also unselects the actor. This becomes especially inconvenient when multiple actors ...

UText3DComponent's Text property access: UE 5.3 broke BP setters. UE 5.6 unneccessarily broke compatibility and incorrectly removed BP getters.

UE - CoreTech - Jul 30, 2025

Class UText3DComponent from the "Text 3D" plugin contains a "FText Text" member which must be set through a SetText() function to correctly update the component's internal state. Up to UE 5.2, "Tex ...

FNiagaraStackGraphUtilities::FindScriptModulesInStack() parameter "OutFunctionCalls" should be a reference

UE - Niagara - Aug 11, 2025

On file [Engine\Plugins\FX\Niagara\Source\NiagaraEditor\Public\ViewModels\Stack\NiagaraStackGraphUtilities.h], function FNiagaraStackGraphUtilities::FindScriptModulesInStack() receives a parameter " ...

Importing FBX that contains a socket from Blender to Unreal, the socket gets rotated by 90° and is scaled by 100

UE - Editor - Content Pipeline - FBX - Sep 9, 2025

Context: Sockets are attach points that can be placed on a Static Mesh to attach an object to the static mesh. Problem: Importing an FBX that contains a socket from Blender to Unreal, the socket ge ...

Division by zero in FAnimNode_StrideWarping::EvaluateSkeletalControl_AnyThread

UE - Anim - Gameplay - Sep 29, 2025

When an Actor's CustomTimeDilation is 0.0, functions FActorTickFunction::ExecuteTick() and FActorComponentTickFunction::ExecuteTickHelper() will call AActor::TickActor() and UActorComponent::TickCom ...

Variant Manager: LevelVariantSets asset corruption after rename or duplicate

UE - Editor - Content Pipeline - Oct 24, 2025

When renaming or duplicating a LevelVariantSets asset that contains a Director Blueprint, the internal DirectorClass reference becomes mismatched. Although the DirectorBlueprint pointer updates corr ...

Outliner eye toggle fails to hide static meshes when Affect Indirect Lighting While Hidden is enabled

UE - Rendering Architecture - Nov 5, 2025

When a static mesh has the property Affect Indirect Lighting While Hidden enabled, toggling its visibility via the Outliner eye icon does not hide the mesh in the editor viewport. The actor remains ...