EDIT: POSSIBLY INVALID - DISREGARD
Summary
Scene Graph sound_component (MetaSound Source presets) plays in UEFN live edit but is silent in every cooked island (private and published), including islands cooked before the change.
Product: UEFN / Fortnite Creative (Scene Graph, Verse) UEFN version: ++Fortnite+Release-42.40-CL-59343437 (Engine 6.0.0-59343437) Fortnite client: current live client on 2026-10-23 (PC, Windows 11) Severity: high. All world audio played through Scene Graph sound components is gone in our live game (doors, containers, captures, sirens, NPC voices).
What happens
Every sound played through a Scene Graph sound_component built from a MetaSound Source preset is silent in a cooked island: private versions (codes) and the live published version. The same sounds play normally in a UEFN live-edit session.
Sounds played through an Audio Player device with a SoundWave still play in the same cooked islands.
Regression evidence
An old private version, cooked on 2026-10-20 before our UEFN 42.40 update (code 8123-0874-6544), used to play these sounds. Tested again on 2026-10-23 it is also silent. Its cooked content hasn’t changed, so the break is on the client / runtime side, not in our project or in the cook.
Our MetaSound assets were unchanged in the period (e.g. MS_Door_Wood_Open last edited 2026-09-26).
The project has no Sound Class, Submix, Sound Mix or Concurrency assets that could mute them.
Setup (how the sounds are made)
184 MetaSound Source assets in the project, each a preset of the engine’s /Metasound/DefaultAssets/Sources/MSS_PlayRandom_Oneshot (or MSS_PlayRandom_Loop), with SoundWaves as inputs and an attenuation asset.
Each one is exposed to Verse as a sound component class and played in one of two ways:
One-shot at a position: a new entity{} with a transform, AddComponents(array{ MS_Door_Wood_Open{Entity := E} }) (AutoPlay on), then SimulationEntity.AddEntities(array{ E }); removed after 4 s.
Loop: a child entity with the component created with AutoPlay := false, then Play() / Stop() from Verse.
Please select what you are reporting on:
Unreal Editor for Fortnite
What Type of Bug are you experiencing?
Scene Graph
Steps to Reproduce
In UEFN 42.40, create a MetaSound Source preset of MSS_PlayRandom_Oneshot with any SoundWave.
In Verse, spawn an entity at a world position with that sound component (AutoPlay true), add it to the simulation entity.
Launch a live-edit session: the sound plays.
Upload a private version and play the code in the Fortnite client: no sound.
Same island: an Audio Player device with the same SoundWave plays fine.
Expected Result
Scene Graph sound components with MetaSound sources play in cooked islands as they do in live edit (and as they did in our 2026-10-20 build).
Observed Result
Scene Graph sound_component (MetaSound Source presets) plays in UEFN live edit but is silent in every cooked island (private and published), including islands cooked before the change.
Platform(s)
PC
Island Code
1045-7404-4448
Additional Notes
Workaround we are shipping
We are moving every sound to Audio Player devices with SoundWaves (a pool moved to the sound’s position), behind one switch, so we can return to the MetaSound components once this is fixed. Please tell us when the fix is live.