Client Crash on "End Game" (v39.50)

[christitze (GraphicSurfer)]

Summary

Since the v39.50 update, the Fortnite client consistently crashes when ending a play session. The game remains completely stable during the active session, but the crash triggers immediately upon exiting the game to return to in-game editing.

This issue is entirely blocking memory calculation, which ultimately prevents pushing any updates to the project. The standard crash reporter modal appears upon crashing, but it does not provide a reference number, error code, or any further details.

Frequency: 100% Reproducible (3 out of 3 attempts so far).

Please select what you are reporting on:

Creative

What Type of Bug are you experiencing?

Assets

Steps to Reproduce

Launch a session from UEFN.

Enter the game and start the session.

Press “End Game” to return to in-game editing mode.

Observe the immediate client crash.

Expected Result

No Fortnite crash

Observed Result

Fortnite crashes

Platform(s)

PC

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[Jimbohalo10]

Hi all,

Further update on this

1. Take a previous published game Feature Example 39.40 in UEFN that was working properly in UEFN
2. Open UEFN
3. Launch Fortnite on PC on 39.50
4. Game starts
5. Screen goes very big only letter F O R T N can be seen
6. Error Match Making Error hash 3 Invalid Session ID
7. Fortnite log is
8. [2026.02.19-17.13.52:771][223]MatchmakingLog: [3da9] Island Manager Shutdown
   [2026.02.19-17.13.52:771][223]MatchmakingLog: [2dfe] Island Refresh Stopped
   [2026.02.19-17.13.52:773][223]MatchmakingLog: Error: [399a] No Local Player
   [2026.02.19-17.13.52:775][223]MatchmakingLog: Error: [2cc3] Invalid core MCP profile
   [2026.02.19-17.13.52:775][223]MatchmakingLog: Error: [2d10] Invalid core MCP profile
   [2026.02.19-17.13.52:780][223]MatchmakingLog: [3d9a] Resetting mode for island [ Island: UEFN Session

10. When running again the Fortnite did same again but looks like the FN game crashed probably with match making but log did not get out to PC
11. UEFN return Session Disconnected

FortniteGameLog3950line19809and3940Backup.zip (567.0 KB)

The fix to large screen is change from 1920 x 1080 from 1280 x 720

39.50 Fortnite Creative ignores Windows screen size 1280 x 720 - General / Issues and Bug Reporting - Epic Developer Community Forums

[Flak]

Thank you so much @Jimbohalo10 - updating the ticket.

[christitze (GraphicSurfer)]

I want to post an update on this. I was able to reach the edit mode ultimately. To achieve this I unchecked “Live Edit” and “Auto Start game” and i removed the Vagabond Jonesy character from my game that seemed to caused a bunch of warnings in my game. Sadly the dude had to go.

[Bug-Reporter]

The status of FORT-1058652 changed to ‘Needs Triage’. We’ve confirmed the issue and it’s waiting to be assigned to someone to fix it.