Summary
The client’s party moved to a new Epic party lobby 20 ms after matchmaking had started for the edit session, and
that party change cancelled the join. Nothing retried it.
| UTC | Client log |
|---|---|
| 18:30:15.071 | Setting launch data { JOIN_MM_SESSION, sessionId=cd4bb21b... } |
| 18:30:23.905 | [Jip.Resolve] RESOLVED ... sessionId=cd4bb21b... role=Host |
| 18:30:23.909 | MemberCoordinator:9C1C6DED...][init_succeeded]; ValidateJoinTarget completed |
| 18:30:23.910 | party V2:f1e35c57… readiness changed to Ready |
| 18:30:23.931 | LogEpicPartyLobbySync: [join_or_create] Party=[cd82bc2a...] Reason=[PartyJoined] |
| 18:30:23.941 | Attempting to leave party [V2:f1e35c57...] |
| 18:30:23.941 | Session changing from [cd4bb21b... EditSession] to [None ... CanNotBeJoinedOrWatched] |
| 18:30:23.941 | ready status changed from Ready to Not Ready (CanceledIslandChanged) |
| 18:30:23.942 | group_invalidated Reason=[local_member_became_unready]; ClientJoin ... Status=CanceledIslandChanged; flow_summary: every step after ValidateJoinTarget Blocked |
| 18:30:24.584 | Joined party [V2:cd82bc2a...-58430987-default], Found Playable Island [playlist_vk_edit], but the session id stays None: no new join |
Both parties hold only this account (no other player involved). It is a client-side race between the Epic party
lobby migration at start-up and the -VK.JoinEditOnLaunch join: the party switch resets the island selection,
which drops the edit session id, and the join is not resumed.
Other client errors in the same second (/DebugUI/* “Could not find SuperStruct”, FortniteClientPilot async load
failed, LogJson: Json Value of type 'String' used as a 'Object', IAS x509 latency tests) also show on good launches
and are not the cause.
Not the cause
- Not our content: upload, validation, cooking and the server’s Verse all succeeded.
- Not a timeout (LF-02): the server was up and waiting for 3 min.
Workaround
Client still in the lobby > 30 s after Launch Session: close the client, wait ~1 min (LF-10), Launch Session again.
Leaving the client open in the lobby between launches (party already settled) avoids the start-up party migration.
Please select what you are reporting on:
Creative
What Type of Bug are you experiencing?
Assets
Steps to Reproduce
- Launch Session in UEFN. Upload went fine (“UpToDate”), the server cooked and started; the island’s Verse ran on the server (18:31:47).
- UEFN launched a fresh Fortnite client (launcher 21:29:38). It reached the lobby with the “UEFN Session” island
selected, but never travelled to the session. - At 18:34:49 the server shut down:
The server shut down because no game clients are connected
(beacon_client_connection_closed_remotely).
Expected Result
After JOIN_MM_SESSION the client joins the edit session even if its party changes during start-up (or
re-applies the launch data after the party settles). Actual: a party lobby change at start-up cancels the join
(CanceledIslandChanged) and the session dies with no clients.
Observed Result
The client’s party moved to a new Epic party lobby 20 ms after matchmaking had started for the edit session, and
that party change cancelled the join. Nothing retried it.
Platform(s)
PC