Launch session - Cook failure out of memory

[thrax207]

Summary

Launch session is very very broken. I’ve tried Asia (UAE) + Europe servers, unfortunately I keep running into
LogValkyrie: Display: ProjectSizeRequest::CancelFlow for 3101256a-4bda-600a-c1db-05b5d6358c1a - Content (re)cook error errors.com.epicgames.cookplugin.cookfailureoutofmemory.

and

PlatformCook: Error: We hit an error while cooking this content
PlatformCook: Error: errors.com.epicgames.content-service.cook_failure
PlatformCook: Error: CookJobId:06e75405-70b2-4ea5-b10d-78a0aa4383f7
PlatformCook: Error: An error occurred while communicating with the game servers (failed to cook module 3101256a-4bda-600a-c1db-05b5d6358c1a (artifact e84840e5-4e37-4d68-9e8a-24d5a41f0fe0:pc) (cookJobId 06e75405-70b2-4ea5-b10d-78a0aa4383f7) with error code errors.com.epicgames.cookplugin.cookfailureoutofmemory).

Please select what you are reporting on:

Creative

What Type of Bug are you experiencing?

Assets

Steps to Reproduce

1. Press launch session in my project

Expected Result

Launch fine

Observed Result

Fails to launch, cook error - out of memory

Platform(s)

PC

Additional Notes

I have had many launch session issues now for 2 weeks already. I reported this and it is not because of the UAE situation. Even Europe servers are running into this issue.

[CodeWiToArTe]

@thrax207

en Europe servers are running into this issue.

Same problem here

[thrax207]

@Flak
I have even rolled back in revision control to a version I can 100% confirm it used to work with launch session before v40.00 update. (557 - ‘add new anims’ by thrax207)
Still won’t launch after v40.00 update with cook error.
We’ve tried through VPN following regions:

1. Asia
2. Europe
3. US

Project id: d1dda1e2-4811-531b-e3c4-b79b32644ffa

I also tried to make a private code, this worked, however I can’t join it in FN (1493-4637-1082)

Our other projects are launching session ‘fine’ (still unstable / slow, 1 month before everything was better) but at least we can use ‘launch session’ through UEFN.

Would greatly appreciate someone from UEFN team stepping in and finding the root cause, hopefully we can fix it for all maps if we find the problem in this one..

[thrax207]

I tried:
Run redirector fix up

Deleting 80% of my current level whats in there

Loading an empty level

Resolved all log containing: ‘LoadErrors:’

Resolved all log warnings: ‘LoadPackage: SkipPackage:’

Clear Source Files Cache - After each retry from above

@Flak any other things the developers shared which we could try? I found this in the v40.00 known issues thread.

[L10NHEART (Lionheart)]

Same problem; did not happen on our project before v40.00

[Bot_lobbies-chan]

Any real update on when this could be fixed..?

None of the stuff here worked

[ChesseTheWasp]

it usually takes them a week or two to move on from the “Unconfirmed” stage

[Jimbohalo10]

hi ,

so eventually a user who does not want to be named sent me his logs

in this log there is

[827]LogAsyncCompilation: Display: BEWARE: AssetCompile memory estimate is greater than available, but we’re running it [SkinnedAsset] anyway! RequiredMemory = 0.000 MiB + 4608.000 MiB, MemoryLimit = 412.761719 MiB

its a 4 Megabyte asset when the maximum is 412 kilobyte Fortnite island should be 100Mb

in 40.00 its flagging previously unseen problems !

[2026.03.26-23.04.15:374][827]LogAsyncCompilation: Display: BEWARE: AssetCompile memory estimate is greater than available, but we’re running it [SkinnedAsset] anyway! RequiredMemory = 0.000 MiB + 4608.000 MiB, MemoryLimit = 412.761719 MiB
[2026.03.26-23.04.15:407][827]LogAsyncCompilation: Display: BEWARE: AssetCompile memory estimate is greater than available, but we’re running it [SkinnedAsset] anyway! RequiredMemory = 0.000 MiB + 4608.000 MiB, MemoryLimit = 408.71875 MiB
[2026.03.26-23.04.15:407][827]LogAsyncCompilation: Display: BEWARE: AssetCompile memory estimate is greater than available, but we’re running it [SkinnedAsset] anyway! RequiredMemory = 0.000 MiB + 4608.000 MiB, MemoryLimit = 408.722656 MiB

[2026.03.26-23.04.15:427][827]LogAsyncCompilation: Display: BEWARE: AssetCompile memory estimate is greater than available, but we’re running it [TextureDerivedData] anyway! RequiredMemory = 0.000 MiB + 1121.000 MiB, MemoryLimit = 411.796875 MiB

[2026.03.26-23.04.15:427][827]LogAsyncCompilation: Display: BEWARE: AssetCompile memory estimate is greater than available, but we’re running it [TextureDerivedData] anyway! RequiredMemory = 0.000 MiB + 1121.000 MiB, MemoryLimit = 411.851562 MiB
[2026.03.26-23.04.15:795][82

[Bug-Reporter]

FORT-1076842 is ‘Closed’ as ‘Fixed’. The issue will be addressed in 40.00.

[LimeAU (Lime)]

I’m still getting the cook failure error

[Jimbohalo10]

hi @LimeAU ,

Looking at the log you kindly have supplied this is not the same error as the original title

To get this investigated this you need a new thread probably called

“Cook failure - Shader artifact error”

(failed to cook module f9c98668-44f1-2e4c-08c2-b38b115daddc

(artifact 2a869688-27f8-41fb-8074-9f736fc7b214:pc)

other sources suggest the the pc on the end is about a shader artifact

In the past made a post on this

Double viewport in UEFN causes shading artifacts - General / Issues and Bug Reporting - Epic Developer Community Forums

This may be a possible answer however you will need the new thread above with all this post copied into the new post. Please tag me @Jimbohalo10 in the message to keep track

[Bot_lobbies-chan]

Still haven’t been fixed