AddChildActorComponent in Construction Script Causes Pending Kill Error

UE - Gameplay - Blueprint - Feb 16, 2016

When using AddChildActorComponent in the construction script of an actor and attempting to get a reference to the child actor that is stored in a variable on Event Begin Play, the editor throws erro ...

After importing morph target: Ensure condition failed: Referencing SkeletalRenderGPUSkin.cpp

Tools - Sep 23, 2017

Hit handled ensure when dragging the slider in Morph Target PreviewLogOutputDevice: Error: Ensure condition failed: DynamicData->MorphTargetWeights.Num() == LODModel.MorphTargetVertexInfoBuffers.Get ...

On the Details Panel of Niagara Function Inputs, the Type selector does not show "Static" types.

UE - Niagara - Apr 7, 2025

Consider a Niagara Function or Module Script containing a Static Switch node. If the "Expose as Pin" option is enabled for its selector variable, an input pin with type "static bool" appears. In one ...

When used with First Loop Start Frame Offset and Use Animation Blueprint, the character will alternate between the specified animation and the reference pose

UE - Anim - Anim in Engine - Jan 30, 2023

If you use StartFrameOffset set to 1 or higher in conjunction with the Use Animation Blueprint, the character's animation will be rough towards the end of the section. Specifically, it seems that th ...

Regression: Asset Action Utility "Supported Classes" setting is not working correctly when "IsActionForBlueprints" is true

UE - Editor - Workflow Systems - Aug 16, 2024

When creating an Editor Utility Blueprint derived from "Asset Action Utility", UE allows the user to override function "IsActionForBlueprints". When it returns true, the "Supported Classes" setting ...

Paper2D performance regression due to TArray resizing

UE - Graphics Features - Aug 16, 2019

We've noticed after upgrading our heavy Paper2D project to 4.22 that tilemap performance has been massively degraded compared to previous versions. After some digging we found out that it's due to a ...

After breaking a level instance without Actor Folders, moving its actors between folders of the world-partition map does not work correctly

UE - World Creation - Worldbuilding Tools - World Partition - Jan 29, 2024

If a standard level (without Actor Folders enabled) is added to a world-partition map (with Actor Folders enabled) as a Level Instance, and then that instance is "broken" so that its actors are inco ...

Sequencer causes 3DWidget on BP vectors to snap to Actor when active

UE - Anim - Sequencer - Nov 15, 2025

When we have Vectors in BP with Show 3D Widget enabled, the Transform Widget would always snap back to the Actor after we move the 3D Widget in-world. [Link Removed] Removing the _DaySequenceActor ...

Code based interfaces do not appear in Interface selection dropdown

UE - Gameplay - Blueprint - May 4, 2017

When adding an interface to a blueprint, only blueprint created interfaces are available. Engine / custom interfaces written in code are not listed. Regression: Yes - custom interfaces are present ...

FViewElementPDI::DrawLine calls for SDPG_World are not rendered in PIE or in Game

UE - Rendering Architecture - RHI - Jan 7, 2026

When View.Family->EngineShowFlags.CompositeEditorPrimitives is false in the function RenderEditorPrimitivesForDPG. This code picks which version of the batched lines to renderconst FBatchedElements ...