41.00 Cooking Error - VerseBuild: Error Only During Cook

Summary

I have started getting the following errors only on cooking after 41.00. There are many of them but this is an example.

"Script error 3506: Unknown member MI_ProgressBar_Linear_Basic_3D_Inst_material in VF_MATERIALS.
Used inside class

But as you can see in the screenshot. it exists in the Assets.Digest.

Please select what you are reporting on:

Unreal Editor for Fortnite

What Type of Bug are you experiencing?

Verse

Steps to Reproduce

All I did was change some verse files and start a session after the update 41.00

Expected Result

No Cook Errors

Observed Result

Cook Errors related to verse but they don’t happen locally

Platform(s)

windows

Island Code

1786-9954-3391

Upload an image

Screenshot 2026-06-06 153558.png

I have the same issue with this material (worked yesterday) and is present in the digest

VerseBuild: Error: C:/build/FortniteGame/Plugins/GameFeatures/57fffa47-4a21-78d1-5063-e7a6b7cbe0bb/Content/petter.verse(584,8, 584,27) : Script error 3506: Unknown identifier Mat_Pet_Bar_Sprite1. Used inside function /sloth_games@fortnite.com/GrowAFarm/operator’.NewSetMeter’.

I believe it is one borrowed from the official UI project but getting cook errors today, wonder if it’s one of the material functions (maybe because it has Icon as a parameter name?)

this causes a cook failure (they are different materials NewMatPetBar and NewMatPetBar1 (the second is a WPO version) but if i remove one of these lines, then the project cooks.

Thanks for the details, folks, getting this checked into.

@Jhon-KOR I had a look at the recent failures and noticed the casing of your VFX_ART directory has changed to VFX_Art. How does this appear on your machine? Have you made any changes with the naming of that directory recently?

Hi @Tom.Noonan .

Thank you for looking into this. It has not changed recently. I even Deleted and synced from scratch. Here is both in the Content Drawer and in the Window Explorer and how it appears in URC.

Thank you

image

If I tried to rename it. this is what happens.

This is what it looks like on the Assets.digest.verse

I tried to rename the folder locally to VF_Art but the editor crashes on start-up once I do. but it looks like it related (When looking at the log file) to verse failing to compile with VF_Art as all of the code references VF_ART

image

i am using no verse and i am getting similar cook issues on memory calculation

stuck here atm

Hi Guys, @Tom.Noonan @Flak

I was wondering if there are any news or potential workarounds. or any other information that could be useful that I can provide.

Cheers,

Thank you

I’m following up and trying to get an update for you now.

In the mean time if you want a workaround you may have some success renaming that folder to something entirely different. I know that brings with it its own set of complications - but it might unblock you if you want to try it

Hi @Tom.Noonan

So, I renamed the Folder VF_ART2 but that was extreme change. had to deal with empty folder and redirectors with over thousands of changes and a pretty large check in.

So, I did a little bit more investigating yesterday; I did a case sensitive search on the intermediate folder for UEFN with the wrong name under “AppData/Local/UnreadEditorFornite” and found the offending folder. under ValkyrieUploadTemp/(hashnumberhere)/content/VF_GAME_ASSETS/VF_Art. So, I just renamed it there and that seems to have worked. interestingly enough. the new VF_ART2 folder is also there empty with all the subdirectories empty as well.

So, this folder structure has to come from somewhere. I found it in .ini file EditorPerProjectSetting.ini. with the entry. ContentBrowserDrawer.JumpMRU=/All/Project/VF_GAME_ASSETS/VF_ART2

Not sure how all of this is related. I didn’t dig any further than that I hope it’s all helpful.

@TrickTyger As discussed on discord. Here are my finding and my workaround.

Cheers,

Interesting, it’s great you were able to figure that out and get yourself unblocked. Sorry this has caused such a headache for you though. Your findings will be very useful, I’ve passed them on

FORT-1113848 has been added to our ‘To Do’ list. Someone’s been assigned this task.