Summary
I’m publishing a custom UEFN island (Duos Battle Royale, 21 teams × 2 players = 42 max) and every matchmaking attempt fails with a server-side timeout after ~13-15 seconds. The queue never finds a match even with 1-3 players queuing together.
Island Code: 4014-4238-2802
Region: NAE
Build: ++Fortnite+Release-39.50-CL-51043566
Current Experience Settings:
TeamSize=Duos
MaxPlayers=42, Matchmaking_MaxPlayersPerSession=42
Matchmaking_MaxTeamSize=2, Matchmaking_MaxTeamCount=21
Matchmaking_MaxSocialPartySize=4
Matchmaking_MinPlayers=1
MatchmakingType=KeepFull
MatchmakingPrivacy=Public, CreativeMatchmakingPrivacy=Unrestricted
bForceStartAtMaxPlayers=False (was previously True)
MMSBackfill=Enabled (was previously Disabled)
AutoStart=10, ForceStartDelay=5
Gamelog Errors (all 4 attempts):
LogMatchmakingServiceClient: WebSocket closed reason: {“code”:4405,“reason”:“match.matchmaking_time_limit_exceeded.405”}
LogMatchmakingServiceClient: MMS error mapped to [1.1.16] unknown
Ticket acquisition and WebSocket connection succeed every time (HTTP 200). The MMS accepts the request but consistently returns queuedPlayers: 0 and times out after the deadline.
Example Attempt (3-player party):
[21:48:21] Matchmaking started (3 players in party)
[21:48:36] WebSocket closed — code 4405: match.matchmaking_time_limit_exceeded.405
Duration: 14.895s | queuedPlayers: 0 throughout
What I’ve already done:
Confirmed bForceStartAtMaxPlayers was True (likely root cause — server required 42 players to form a match). Changed to False.
Changed MMSBackfill from Disabled to Enabled.
Verified all device/Verse code has no compile or cook errors.
Memory budget: 81,921 / 100,000 (passing).
Verse compiles: all successful, 0 failures.
Publishes: “Successfully activated content on all platforms.”
Questions:
After fixing bForceStartAtMaxPlayers=False and MMSBackfill=Enabled, is there any propagation delay before the MMS picks up the new configuration?
Are there any other settings that could cause the MMS to reject match formation with small player counts (1-3 players)?
Does Matchmaking_MinPlayers=1 actually allow a solo player to start a match, or is there a hidden minimum?
Any guidance appreciated. Happy to share full Gamelog excerpts.
Please select what you are reporting on:
Unreal Editor for Fortnite
What Type of Bug are you experiencing?
Matchmaking
Steps to Reproduce
Steps to Reproduce:
Create a UEFN Creative island with custom matchmaking settings (Duos, 42 max players, 21 teams)
Set bForceStartAtMaxPlayers=True and MMSBackfill=Disabled in Experience Settings
Publish the island successfully (cook passes, memory passes, activation succeeds)
Launch Fortnite client and select the published island (code 4014-4238-2802)
Queue for matchmaking solo or with a small party (1-3 players)
Observe: MMS WebSocket connects, queuedPlayers stays at 0, and after ~14-15 seconds the connection closes with code 4405: match.matchmaking_time_limit_exceeded.405
Repeat — fails consistently across all attempts
Expected: Match forms with available players and backfills remaining slots
Actual: MMS never forms a match; times out every attempt
Expected Result
Expected Result:
Matchmaking forms a match with the available players (1-3) and starts the game
Remaining player slots fill via backfill during gameplay
Players load into the island and the game begins within the queue timeout window
Observed Result
Actual Result:
MMS ticket is acquired successfully (HTTP 200)
WebSocket connects to MMS server
queuedPlayers remains at 0 for the entire duration
After ~14-15 seconds, WebSocket closes with error code 4405: match.matchmaking_time_limit_exceeded.405
Players are returned to the lobby with a “Matchmaking Error” message
This occurs 100% of the time across solo, duo, and trio party sizes
Platform(s)
PC Windows 11
Attempted matchmaking platforms: IOS, Windows, PS5
Island Code
4014-4238-2802
