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

[Jimbohalo10]

Summary

Many users of UEFN , which is based on UE 5.5 Standard are experiencing problems with a startup with a shortcut made from Epic Launcher

Please select what you are reporting on:

Unreal Editor for Fortnite

What Type of Bug are you experiencing?

Stability

Steps to Reproduce

UEFN crashes on startup due to incorrect parameters for DX11 Shader Model 5 and DerivedData cache.
Starting UEFN on Window11 from created by Epic Launcher Shortcut may crash on some PCs

Expected Result

To run like UE 5.5 and use DX11 SM5

Observed Result

Uses DX12 SM6 and Nanite support which is NOT supported correctly in Windows 11

Platform(s)

ONLY Windows 11

Additional Notes

See links to posts below

[Jimbohalo10]

hi @Fallen-Champ and ALL

Fatal Error opening UEFN Project - General / Issues and Bug Reporting - Epic Developer Community Forums

the command for the shortcut in Copy the line below into
the (Properties - > Target) Target box is

"C:\Program Files\Epic Games\Fortnite\FortniteGame\Binaries\Win64\UnrealEditorFortnite-Win64-Shipping.exe" -d3d11 -sm5 -DDC=None

Then click the button “Apply”, then click “Ok”

-DDC=None will stop Derived Data Content

If you want to restart
-DDC=Cold will stop Derived Data Content and reload cold will rebuild the Derived Data Content

Feedback from users requested how to set “Run as Administrator” to be permanently selected
This is the original patched picture for the switch to DX11

In this picture click “Advanced” to give the picture below

Tick/Click the box marked “Run as administrator” then Click “OK”
Then click Apply and OK to return to desktop

When clicking the shortcut the prompt asks if
“Do you want to make changes to your device?” Click “Yes”

UEFN will now “Run as Administrator” and may stop login failures

[Fallen-Champ]

Thank you for the reply but unfortunately my tech skills are not great

Had a friend online talk me through some of this and neither worked for me

Had " at the start before F (its on my F drive)

Tried both of those but neither worked so unsure now, will have a read through this again but out of ideas right now

Thanks for the help though, I appreciate your time

[Fallen-Champ]

Also I am on Windows 10 does that change anything with what was posted above even though we could not get it working, tried re-install again but wasting my time.

UE and Fortnite the game work fine, it’s very frustrating

[Jimbohalo10]

Hi @Fallen-Champ
Updated the text so that you can click the “copy icon” the instructions are updated

[Fallen-Champ]

@Jimbohalo10

-d3d11 -sm5 -DDC=None

Thank you again for the help, unfortunately what should be seconds is a nightmare for me, when I re-installed UEFN I saw no area that asked where it should go so I let it install.

My PC is an odd setup my brother in law did it, I have a S/E/F drive
Seems UEFN and FortniteGame are on F (they used to be on C but something kept eating into the HD space so they are on F now)

So that’s a screen of where UEFN is located but nothing like the shortcut at the top.

I added that at the end so it looks like this
F:\Fortnite\FortniteGame\Binaries\Win64\UnrealEditorFortnite-Win64-Shipping.exe" -d3d11 -sm5 -DDC=None

It just says something wrong with the shortcut - really sorry I am not a critical thinker and can’t understand or work out a way around it, I did try the link with a C at the start but no good plus UEFN not on my C drive.

Really sorry to be a pain, hoping you know of a simple solution

Thanks again for your time

[Jimbohalo10]

hi @Fallen-Champ

"F:\Fortnite\FortniteGame\Binaries\Win64\UnrealEditorFortnite-Win64-Shipping.exe" -d3d11 -sm5 -DDC=None

Looking at your error. The front of the string should contain a double Quote (")

See the text above converted to your path

[Fallen-Champ]

Fatal error: [File:D:\build++Fortnite\Sync\Engine\Source\Developer\DerivedDataCache\Private\DerivedDataBackends.cpp] [Line: 197]
Unable to use default cache graph ‘InstalledDerivedDataBackendGraph’ because there are no readable or writable nodes available.

0x00007ff6b24836c0 UnrealEditorFortnite-Win64-Shipping.exe!UnknownFunction
0x00007ff6b2483a54 UnrealEditorFortnite-Win64-Shipping.exe!UnknownFunction
0x00007ff6b24a039f UnrealEditorFortnite-Win64-Shipping.exe!UnknownFunction
0x00007ff6b24aec2e UnrealEditorFortnite-Win64-Shipping.exe!UnknownFunction
0x00007ff6bdeba820 UnrealEditorFortnite-Win64-Shipping.exe!UnknownFunction
0x00007ff6bdeb2813 UnrealEditorFortnite-Win64-Shipping.exe!UnknownFunction
0x00007ff6bdeb2a9a UnrealEditorFortnite-Win64-Shipping.exe!UnknownFunction
0x00007ff6bdeb390d UnrealEditorFortnite-Win64-Shipping.exe!UnknownFunction
0x00007ff6bdebd1d4 UnrealEditorFortnite-Win64-Shipping.exe!UnknownFunction
0x00007ff6d5186382 UnrealEditorFortnite-Win64-Shipping.exe!UnknownFunction
0x00007ffa19cb7374 KERNEL32.DLL!UnknownFunction

Unfortunately it still crashes at 7% even using that line of text

I thought the above was an image pasting in but it’s shown text - unsure why it says (File:D:\build as D is dvd drive

This is what I get (bottom image) - crash at 7% every time using that line of text, oddly when I click on Apply that stays grayed out and the text highlighted blue - on looking the " before the F disappears so unsure why that happens, if I try to type " that back in before the F it says invalid, maybe it can’t be fixed.

[Jimbohalo10]

hi @Fallen-Champ
The UEFN crashes are due to the wrong path on F:

Therefore your PC needs the new path added in Windows Explorer

on F:
create directory , not quotes,“Program Files”
Then go into “F:\Program Files”

on F:
create directory , not quotes,“Epic Games”

Now go in Windows File Explorer
copy F:\Fortnite to F:\Program Files\Epic Games\Fortnite

now update the short cut to Target to

F:\Program Files\Epic Games\Fortnite\FortniteGame\Binaries\Win64\UnrealEditorFortnite-Win64-Shipping.exe" -d3d11 -sm5 -DDC=None

[Fallen-Champ]

Thank you for this extra info, I felt really embarassed that I could not grasp what was needed, all I had done previously was place in ""F

I really appreciate your help with this, lately I have been using my laptop every day with UEFN which. isn’t great - thank you so much for been patient I honestly mean this, hoping I can get to there now so will let you know soon - Cheers

So I created the 2 folders in F and copied Fortnite Game over

Then went into the folder and tried properties on the UEFN shortcut but the Target option was not there so created a new Shortcut seen in this image

Have that YEFN shortcut on my desktop now, placed that text you kindly provided and copy pasted it into the Target properties but got that error.

something else I now have Fortnite folder on F saying 110GB & Program Files Epic Games Fortnite folder saying 110 GB - do I delete the one I moved as I don’t see a redirect option when right clicking on the folder?

Unfortunately I feel I am too stupid to be able to sort this out, I am a mature gamer been around gaming some years and with this & some recent UEFN issues am wondering if I have some kind of mild autism, never felt this my whole life but these recent events have me wondering why I can’t do simple tasks.

Thanks again for helping I really don’t want to have to buy a new PC right now but can’t seem to grasp this - hoping you will get me there though

---

Edit - just done this again from the start, was not sure on creating the shortcut so searched via google which said right click on desktop select new - shortcut then browse or type in, I browsed to it in the binaries folder

Typed in F:\Program Files\Epic Games\Fortnite\FortniteGame\Binaries\Win64\UnrealEditorFortnite-Win64-Shipping.exe" -d3d11 -sm5 -DDC=None but no good I got this below.

So went with the correct location without that code at the end and named the shortcut

So now on desktop right click on newly created shortcut - Target says
“F:\Program Files\Epic Games\Fortnite\FortniteGame\Binaries\Win64\UnrealEditorFortnite-Win64-Shipping.exe”

Start In says
“F:\Program Files\Epic Games\Fortnite\FortniteGame\Binaries\Win64”

So i swapped Target info to now say
F:\Program Files\Epic Games\Fortnite\FortniteGame\Binaries\Win64\UnrealEditorFortnite-Win64-Shipping.exe" -d3d11 -sm5 -DDC=None

on pressing apply I get this

So if I leave that bit of code off at the end and just have the link
“F:\Program Files\Epic Games\Fortnite\FortniteGame\Binaries\Win64\UnrealEditorFortnite-Win64-Shipping.exe”

I get the Fatal Error

So it has to be something to do with " -d3d11 -sm5 -DDC=None
With that I can’t progress without it Fatal Crash - is there any other way even if it means going through a sequence clicking on things to start I don’t mind just so long as I can get into the editor without the 100% crashes every time

Just realized that the Target and Start in both had " before the F so I put that in before the F on your text, thought I had cracked it as it started to load but fatal error at 7% again

Is copy pasting that in acceptable or does it have to be typed in as I can’t see anything I have done wrong?

[Fallen-Champ]

I deleted everything and installed the new updated version at F Program Files Epic Games Fortnite etc

Tried that line of text again and got this (image added) - looks the same as before but there is a little extra text it also says “Add -DDC-ForceMemoryCache to the command line to bypass this if you need access to the editor settings to fix the cache configuration” (don’t think that was there before)

The Target I currently have is
“F:\Program Files\Epic Games\Fortnite\FortniteGame\Binaries\Win64\UnrealEditorFortnite-Win64-Shipping.exe”

If I take out " before F I get this below

Start In looks like this
“F:\Program Files\Epic Games\Fortnite\FortniteGame\Binaries\Win64”

Where you said - Observed Result
Uses DX12 SM6 and Nanite support which is NOT supported correctly in Windows 11

Someone said they had to switch to DX11 so they could launch UEFN

Is there an option where I turn off DX12 / Nanite as my desktop was always on Medium settings anyway I never had DX12 on so is there a different way around this other than the one discussed above which I can’t seem to grasp?

---

Unsure if this would make much difference - the image you posted saying click the button, this is something I never did as not seeing the button so I was doing CTRL + C then CTRL + V - is there any difference in doing it that way could that be a factor?

Thanks again for the help, maybe I have to bite the bullet and get a new PC but would rather not rush into it if I can get around this and somehow launch UEFN on current desktop.

[Jimbohalo10]

hi @Fallen-Champ ,
the Fortnite 32.00 was updated on 6th November .
In Windows File Explorer navigate to
F:\Program Files\Epic Games
delete folder containing old version 31.40
F:\Program Files\Epic Games\ Fortnite

Open Epic Games Launcher as Administrator as described above

Store → Library

When uninstall completed
Click the 3 dots again
Then Install and set the drive from C: to F: as in picture below

[Fallen-Champ]

Thank you but for me no good at all - after deleting the folder I could not uninstall as it was already gone so that was throwing up an error, re-booted PC and could then re-download which takes me roughly half a day on my desktop.

This really confused me “Open Epic Games Launcher as Administrator as described above”
Reading the above this image had -d3d11 at the end of the target so I put that in - unsure if I was supposed to or not.

It resulted in this - same ■■■■ different day for me

So with -d3d11 at the end of the target it got to 8% then crashed, I then took the text out ran as administrator and it was an instant crash so with or without no difference.

So fed up now, it is embarrassing trying my best to do things right but must be doing something wrong, if anyone else knows of a 100% way of getting this to work can they please give a detailed guide as the above for some reason has not worked for me.

Jimbohalo10 thank you for been patient but for me nothing has worked, I did not install DX12Shaders with the install unsure if that would make any difference, it’s been over 10 days and become exhausting now, crazy that I can’t grasp this and will now no doubt have to buy a new PC just to USE UEFN on it.

Thanks again for your time - if someone else knows what I am doing wrong then I am all ears as I have tried doing the above.

[Jimbohalo10]

Hi @Fallen-champ
This just looks like needing a new PC.
Looks like everything has been trashed by the O/S