The Open Level command is causing Android devices to freeze up

UE - Platform - Mobile - Dec 1, 2014

If you use the Open level node in the newest promoted build, once the project is deployed to an Android device, when triggered with a UMG, the project will freeze and be unplayable. Issue does not ...

Calling a child's child in a child blueprint from a spawn actor from class node that is being called back to the child causes an error

UE - Gameplay - Blueprint - Jun 29, 2015

Calling a child's child in a child blueprint from a spawn actor from class node that is being called back to the child causes an error. Basically, when using the spawn actor node referencing the chi ...

"Play" node does not restart the animation when triggered

UE - Gameplay - May 13, 2015

"Play" node in the Blueprint Editor does not restart the animation when it is triggered. Problem crops up when somebody wants to replay the animation assigned to the skeletal mesh more than once. ...

Deleting the code files for a custom component from a project will result in an Engine crash when trying to open any Blueprint using that component.

UE - Gameplay - Blueprint - Feb 20, 2015

Adding a custom component to a Blueprint and then deleting the code class defining that custom component from the project will crash the Editor any time you try to open a Blueprint containing that c ...

Niagara Particles in Mesh Shape Don't Render in Scene or Editor Preview

UE - Niagara - Dec 19, 2019

Niagara particles aren't rendered in the Niagara Editor Preview or the scene when an emitter is in it. Found in 4.24.1 CL#10756747 Reproduced in 4.25 Main CL#10808197 ...

[MetaSounds][Wave Player] - Looping sound waves is not sample accurate

UE - Audio - MetaSounds - Aug 8, 2022

When playing the two metronome sounds, it is expected that when the 1bar asset loops, it will stay in time with the 12 bar asset; however, instead phasing begins to occur. This does not occur when ...

Lumen indirect lighting artifacts when far from world origin

UE - Graphics Features - Lumen - Feb 6, 2024

Lumen seems to not be using Large World Coordinates somewhere. The Lumen Scene develops artifacts at large distances (5000 KM) from the world origin. ...

Distant mesh / vista have visible Lumen bounces

UE - Rendering Architecture - Jun 15, 2024

Objects far outside of the Lumen Scene don't temporally accumulate screen traces, leading to heavy flickering. It appears that the temporal reprojection is failing when comparing the depth in "Scree ...

UV Offset Effect Material in RetainerBox Causes Visual Artifacts in Editor Preview

UE - Editor - UI Systems - UMG - Apr 22, 2025

When a UV Offset is applied in a RetainerBox effect material, visual artifacts appear only in the editor — not at runtime — if a widget with a dotted preview outline (like CanvasPanel) is placed dir ...

Changing the value of a parent class variable does not update after hot reload

UE - Gameplay - Blueprint - Mar 4, 2015

When the value of a variable defined in a parent class is changed inside of the child class, the value is not updated in a BP of the child after hot reloading. ...