UEFN not launching

[FreshBeezy]

Summary

When I try to start the UEFn, it loads briefly, but then closes automatically without any error message. The Epic Games Launcher shows UEFN as running, but I’m unable to access it. I tried uninstalling, verifying game files but none work. Could anybody please help me with this.

Please select what you are reporting on:

Creative

What Type of Bug are you experiencing?

Assets

Steps to Reproduce

I tried uninstalling, verifying game files but none work.

Expected Result

Being able to create on UEFN

Observed Result

?

Platform(s)

Gaming Laptop

[Flak]

Could we get your logs? How to get your Fortnite logs

[FreshBeezy]

Thanks for your reply. I tried to send my logs, however once I type \AppData\Local\UnrealEditorFortnite\Saved\Logs and press enter, it says the log is not findable. Any idea how to fix this?

[Jimbohalo10]

hi @FreshBeezy ,
The directory AppData is Hidden and needs to be unhidden or pasted directly into Windows File Explorer

Try

1. Press the Windows key and tap the R key, this will open a run window
2. Type %localappdata%
3. Navigate to C:\Users\jimgi\AppData\Local\UnrealEditorFortnite\Saved\Logs
4. Upload the latest UnrealEditorFortnite.log or
5. Right-click the Logs directory “Send to” select Compressed folder
6. Upload the compressed file

[Jimbohalo10]

hi @FreshBeezy ,
The problems you described are most likely the Graphics controller and the procedure will possibly fix the problem.

Firstly try the Epic Support article
How do I force Fortnite to use DirectX 11? - Fortnite Support (epicgames.com)

Then try this
[Solved] How to fix Fatal Errors in UEFN related to Graphic Cards and Shaders and Derived Data problems

This is set up in a Windows ShortCut

This is highly technical but it usually fixes the problem

This has been rewritten for UEFN (Unreal Engine Fortnite), which is based on UE 5.5

You need to change the Base system on start-up

Go into Windows File Explorer copy and paste the path

C:\Program Files\Epic Games\Fortnite\Engine\Config

Click on to Highlight “BaseEngine.ini”. Right Click “Open with” select Notepad

Control+F find “WindowsTargetSettings” at line 2840

[/Script/WindowsTargetPlatform.WindowsTargetSettings]
+D3D12TargetedShaderFormats=PCD3D_SM5
+D3D11TargetedShaderFormats=PCD3D_SM5
bEnableDistanceFields=true
bEnableRayTracing=true
bTarget32Bit=false

Add the line at the beginning

DefaultGraphicsRHI=DefaultGraphicsRHI_DX11

so this section looks like

[/Script/WindowsTargetPlatform.WindowsTargetSettings]
DefaultGraphicsRHI=DefaultGraphicsRHI_DX11
+D3D12TargetedShaderFormats=PCD3D_SM5
+D3D11TargetedShaderFormats=PCD3D_SM5
bEnableDistanceFields=true
bEnableRayTracing=true
bTarget32Bit=false

Type Control + s. Save the file by closing Notepad and restarting UEFN Editor.
Your system now uses DefaultGraphicsRHI_DX11

If you like using the Windows Command shell use the command to pen the file
notepad C:\Program Files\Epic Games\Fortnite\Engine\Config\BaseEngine.ini

[Jimbohalo10]

hi @FreshBeezy ,

Firstly try the Epic Support article
How do I force Fortnite to use DirectX 11? - Fortnite Support (epicgames.com)

If the change for UEFN works it is highly likely that Fortnite will need Settings will need changing.
In any Fortnite Island once loaded. Press the ESC key

When Fortnite starts this will be using the earlier DX11 DirectX 11.

The problem is mainly related to the Windows 11 version of DirectX 12 Ultimate drivers and interaction with graphics card drivers

[FreshBeezy]

@Jimbohalo10

Firstly try the Epic Support article

Hi, thank you for your support.

I followed the instructions in the Epic Support article, but it didn’t resolve the issue. When I navigated to C:\Program Files\Epic Games\Fortnite\Engine\Config in Windows File Explorer, instead of finding BaseEngine, it showed StageBuild.

Could you please help me troubleshoot this further?

Thanks in advance!

[Jimbohalo10]

hi @FreshBeezy ,
Try the update to new shortcut way to start UEFN with DX11 default

[Flak]

Could you also try running as administrator?

1. Right-click your Epic Games Launcher shortcut.
2. Click Run as administrator.
3. Launch UEFN.

[FreshBeezy]

Hello,

I’ve tried all the solutions from the Epic Support articles, but unfortunately, nothing is working. I really want to continue creating in UEFN, but it’s impossible at the moment due to these issues. None of the steps I’ve taken have resolved the problem.

Do you think reinstalling Windows could help? I’d appreciate your advice on how to proceed.

Thank you in advance!

[FreshBeezy]

Hi,

I’ve gone through all the suggested solutions from the Epic Support articles, but nothing seems to fix the issue.

Would reinstalling Windows be a potential fix? I’d appreciate any further guidance you can offer.

Thanks in advance!

[Jimbohalo10]

hi @FreshBeezy ,
If you have tried starting UEFN using the article
[Solved] How to fix Fatal Errors in UEFN related to Graphic Cards and Shaders and Derived Data problems

The answer to the operating system problem is to buy the cheapest Windows 10 Home Edition copy and install it on your PC.

For my testing, the only reason for using Windows 11 is to find workarounds to allow people to use Windows 11 for developers who cannot go back to Windows 10.

Keep in mind that all your projects must be backed up to Unreal Revision Control and NOT ON OneDrive of Windows 11.

URC (Unreal Revision Control) Sync function requires a reliable fast connection (NOT Oceana) at a quiet time.

If you cannot understand URC then DONT reinstall Windows

There have been so many problems attributed to OneDrive that a message now appears on opening a project to warn of using Cloud Base storage because if networks stop working you lose your project!.

[FreshBeezy]

Hi Jimbo,

I’m currently receiving an error message after running UEFN. Could you please help me troubleshoot and resolve this issue?

Thanks!

this is what it says;

GPU Crash dump Triggered

UnrealEditorFortnite_Win64_Shipping
UnrealEditorFortnite_Win64_Shipping
UnrealEditorFortnite_Win64_Shipping
UnrealEditorFortnite_Win64_Shipping
UnrealEditorFortnite_Win64_Shipping
UnrealEditorFortnite_Win64_Shipping
UnrealEditorFortnite_Win64_Shipping
UnrealEditorFortnite_Win64_Shipping
UnrealEditorFortnite_Win64_Shipping
UnrealEditorFortnite_Win64_Shipping
UnrealEditorFortnite_Win64_Shipping
UnrealEditorFortnite_Win64_Shipping
UnrealEditorFortnite_Win64_Shipping
UnrealEditorFortnite_Win64_Shipping
kernel32

[Jimbohalo10]

hi @FreshBeezy
looking in the past
UEFN crash on startup assertion failed. - General / Issues and Bug Reporting - Epic Developer Community Forums

The Dx12 have GPU errors, the main errors are in SM6 hence use SM5 which my pc uses

[Solved] How to fix Fatal Errors in UEFN related to Graphic Cards and Shaders and Derived Data problems

Windows 11 usually has these errors and Windows 10 works fine.
Some software based on UE5 works well since 2018,
The Official equivalent needs Windows 11 and Directx12 because the shaders are model 6.5+

My development is done on Windows 10 latest and UEFN fault finding on Windows 11.
There was once an idea that this was because Texture - Static mesh show be Power 2 of 2
2023 projects crash more often but nobody really knows why