Unable to launch a session : "We hit an error while cooking this content errors.com.epicgames.content-service.cook_failure"

Summary

Since the update 35.20, I’m unable to launch a session or build a private code of my island.

The session, start but after the project has been send, I get the error in the screenshot attached to this post.

Please select what you are reporting on:

Unreal Editor for Fortnite

What Type of Bug are you experiencing?

Other

Steps to Reproduce

Launch a session

Expected Result

Session start without error

Observed Result

The session start but with an error

Platform(s)

Tried on PC, Xbox, Xbox cloud and Luna

Upload an image

Additional Notes

When I try to launch the session, before I was getting an other error already post here : Validation error from outdated files in sys/versions (regression?)