New Update: Many players unable to matchmake

LargeRedApe · September 23, 2025, 3:42am

Hey, i’m working on the same project as Zebs (Above)

We’ve been blocked on last-gen consoles (Switch, PS4, Xbox One) since July 20, 2025, when there was an outage with the cook system (valkyrie-cook-api).

Our project worked fine up to revision 2748, but from 2749 (July 20 - 9:35am) onwards it has never worked on last-gen consoles (though PC still works).
The problem started the same morning as the URC update (linked: https://forums.unrealengine.com/t/major-issues-with-new-version-of-revision-control-urc2/2601917/41) and at the same time as widespread candidate module validation failures. (https://forums.unrealengine.com/t/failed-to-cook/2611253/2)

Current Symptoms

PC sessions launch fine (private & published).

Switch/PS4/Xbox One fail with:

Out-of-order slow task construction/destruction: destroying 'Matchmaking ...' but 'Uploading Assets' is at the top of the stack
LogValkyrie: Error: FlowStep_ResolveSessionCandidates(): Candidate module [562929a6-493e-2b6d-91eb-ceb08b29db50] failed validation with error: [http_error_500: valkyrie-cook-api.prod.ucs.on.epicgames.com]

Even publishing an empty scene still fails on last-gen consoles with the same error.

What we’ve tested

Deleted Verse, SceneGraph, Data Layers, Icehook content, shaders, heavy VFX.
Reduced project size & actors.
Last working build (rev 2748) → same projectId + same moduleId.
Since the July 20 cook outage, all syncs bind to the same module ID (562929a6-493e-2b6d-91eb-ceb08b29db50) which now fails validation only on last-gen.

Request

Could you please:

Investigate whether module 562929a6-493e-2b6d-91eb-ceb08b29db50 was corrupted during the July 20 cook outage?
Invalidate/recook or reset this module binding for our project (projectId: 59d327d9-47d0-37c8-1747-5ab22f2b9c94) so it can target last-gen again.
Confirm if there is a known issue with the URC update + candidate module validation on last-gen.

This issue has blocked us for months, and since it reproduces even on empty maps, it looks like a backend module validation problem rather than our content.

Thanks so much for digging into this.