Fatal Error opening UEFN Project

hi @Cleverlike_Studios
Working on a similar problem

[2024.10.18-02.34.52:241][ 0]LogShaderCompilers: Display: Compiling shader autogen file: C:/Users/jxxx/AppData/Local/UnrealEditorFortnite/Intermediate/ShaderAutogen/PCD3D_SM5/AutogenShaderHeaders.ush
The Shader settings are wrong yours is PCD3D_SM6

[2024.10.09-16.12.47:884][ 0]LogShaderCompilers: Display: Compiling shader autogen file: C:/Users/ixxx/AppData/Local/UnrealEditorFortnite/Intermediate/ShaderAutogen/PCD3D_SM6/AutogenShaderHeaders.ush

First, try the easier shortcut to UEFN and add DX11 as an Additional Parameter

in this picture, copy and paste the line below we need to add Dx11 and sm5
to give -d3d11 -sm5 at the end of Target box

"C:\Program Files\Epic Games\Fortnite\FortniteGame\Binaries\Win64\UnrealEditorFortnite-Win64-Shipping.exe" -d3d11 -sm5

Now start UEFN from the Desktop Shortcut

This is a highly technical soloution to the problem only if you are comfortable

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

You need to change the Base system on startup
go into Windows File Explorer copy and paste the path C:\Program Files\Epic Games\Fortnite\Engine\Config
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

Make sure you have PCD3D_SM5 NOT PCD3D_SM6

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 on closing notepad and restart UE Editor.
You system now uses DefaultGraphicsRHI_DX11

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