Broken session launching (fake validation error)

Summary

This bug makes it so the player in UEFN is unable to launch as session. since epic support say they wont help with this and there is no known fix, your map is pretty much broken and u can not fix it

Please select what you are reporting on:

Unreal Editor for Fortnite

What Type of Bug are you experiencing?

Live Edit

Steps to Reproduce

Open UEFN and load an existing project, Attempt to launch a Play Session (Session → Launch Session) Observe that the project fails to load the map and displays a validation error even though the project is fully valid when doing just the validation scan. Deleting %LOCALAPPDATA%\UnrealEditorFortnite\Saved, Intermediate, and Editor folders
Cloning the project and renaming .uefnproject
Restarting UEFN and the PC
Attempting to publish a private version of the map
None of the fixes above resulted in a solution and make zero difference in the outcome.

Expected Result

Expected Result (what should happen)
The project should successfully launch a Play Session.
The map should load correctly in UEFN and in Fortnite.
No “Failed to resolve validation session” error should occur.
The session should generate a new session ID allowing normal editing and private play.

Observed Result

UEFN displays the error:

Failed to resolve validation session

The project loads into the session partially, but the map does not appear.

Attempts to launch a private version of the map fail.

Cloning the project or clearing local cache does not resolve the issue.

Logs indicate a stuck session on Epic’s backend:

session cannot be resolved until all candidate validations have been triggered

Platform(s)

windows

Island Code

Stuck session prevents island code from being assigned

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