I wanted to push an update to an existing project that I have been working on, but it looks like my project has somehow completely broken.
I went over the logs of UEFN, Epic Games Launcher and Fortnite, yet they do not give me a clear direction as to what is happening. From what I was able to discover from logs however, is that UEFN attempts to launch a Fortnite session and appears to be failing to do so. Common fixes have been tried, but at this point I dont know what else to try.
I was able to investigate and find possible culprits through logs:
‘EpicGamesLauncher.log’ - ERROR - “[414]LogRunningAppService: Display: Dead foreground process [25796] F:/Program Files/Epic Games/Fortnite/FortniteGame/Binaries/Win64/urc.exe for app F:\Program Files\Epic Games/Fortnite”.
Additionally another error is displayed - ERROR - “LogAutoUpdateService: CheckForUpdates: At least one application or editor doesn’t allow auto-updates: AppId: fn:4fe75bbc5a674f4f9b356b5c90567da5:Fortnite”,
“[ 93]LogEOSMessageService: Error: Unable to find port.”
2. ‘FortniteLauncher.log’ - WARNING - "WARN msg=“error running fortnite” err=“exit status 3” gets displayed after attempting to run ‘FortniteClient-Win64-Shipping_EAC_EOS.exe’ " . This file is tried to be executed multiple times before it finally crashes due to ‘heartbeat’ being timed out I assume (ERROR - “LogCore: Warning: Failed to reach checkpoint within alotted time of 600.00. Triggering hang detector.” through log in ‘FortniteGame.log’.
On my secondary computer it also fails but with exit status “0xeeac1018”.
Please select what you are reporting on:
Unreal Editor for Fortnite
What Type of Bug are you experiencing?
Matchmaking
Steps to Reproduce
Open UEFN and launch a session. It gets stuck in “Connecting…” screen and crashes there in about 10 minutes.
Expected Result
Fortnite session is launched successfully to validate functionality and calculate memory.
Observed Result
Fortnite crashes with unexpected error message. UEFN stays open.
Platform(s)
PC
Island Code
9510-3204-1034
Additional Notes
Although I did re-install my project to a separate drive, I have performed multiple reinstalls to both drives and that does not appear to be related, as I also tested on my secondary computer and encounter the same Fortnite crash there when launching a session.
As an additional note, my other projects (a lot smaller) appear to launch just fine. And this was launching fine the last time I was working on it (23.03.25).
I have tried to validate my project, deleted the project under “../Fortnite Projects” to get a fresh version, use previous versions through URC, built landscapes, use a different computer, built HLODs but nothing seems to work.
Did some additional digging into ‘FortniteGame.log’ logs, and found out that upper part of logs is full of the following error message:
LogDownloadOnDemandGameplay: Verbose: [3d2c] Failed To create Download On Demand Project. Link entry was deemed invalid
So my hypothesis is that for some reason my connection to this project is either marked as ‘invalid’ (authentication maybe?) or the link to my project does not exist in Epics side..? And it keeps trying to connect to it (there’s thousands of this message in logs) until it finally reaches timeout and causes Fortnite to terminate my requests by ‘crashing’.
I’ve never had such an issue before and I would really appreciate some help - I can provide any logs necessary to get this resolved ASAP
Since I’m not the only one impacted by this, can we get some confirmation that this is being investigated? Most likely this is caused by the latest 34.20 patch.
Yes, I am still facing these issues.
There were some validation issues that arose after today’s update that I resolved, but the same errors messages from before still persist.
There were changes done to HUD Controller logic - although Verse now gives warning for using previous logic of hiding HUD Controllers (i.e. using function ‘.HideHUDElements()’), there are still no warnings or errors given during validation if you have placed ‘HUD Controller Device’ inside your ‘Outliner’/game map. Deleting HUD controller allows users to connect to the island hub when launching (the small box with trees and patterned blue floor) - without this change, Fortnite window would not even get that far with loading you to your island.
I randomly stumbled on THIS bug report - people seem to be experiencing problems with textures larger than 1024x1024. I remembered that after UEFN update on 08.04.2025 it was giving me warnings regarding imported texture dimensions, so I decided to test this out.
Validation gives no dimension warnings regarding this after you change imported textures to 2048x2048, but unless you downgrade them to 1024x1024, your session would not launch successfully, resulting in infinite “Loading..” screen until it eventually reaches hearbeat after 600 seconds and crashes Fortnite window.
I do believe UEFN should allow textures at least in dimension 2048x2048, as 1024x1024 makes textures appear blurry and non-polished.
After these changes, I was still unable to connect - now clicking on ‘Launch session’ started showing “Exit session” (as if I should have the project up and running). I am also not the only one that faced this problem, as also mentioned here.
I discovered a workaround regarding this - if you launch Fortnite before opening UEFN and then click later ‘Launch session’, this resolves this problem. I was finally able to connect to my project, yay!
So, why is this happening? After digging through Fortnite logs, it seems that there has been some major change regarding session validation and launching to your project after UEFN version 34.20 was released. Local project validation and what is happening on Epic’s side seem to have some drastically different requirements, which causes a wide variety of problems for different users.
Please let me know once this information has been forwarded to relevant parties. Thank you!
