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

2 Likes

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,

3 Likes

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

2 Likes

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