UEFN startup error

Summary

UEFN build 42.20-CL-58011042, installed at D:\Fortnite. Launching through Epic produces all three errors described in FORT-1152398. Reinstalling and verification did not help. All 11,840 UEFN manifest-listed files exist. Independent SHA-1 checks of 463 installed startup binaries and package files matched their local manifests, including 99 UCAS files. Process Monitor shows successful reads of UEFNFortniteGame-WindowsUEFN.pak. No startup log was generated with explicit logging arguments. Please investigate whether this is FORT-1152398 and provide a workaround.

What Type of Bug are you experiencing?

Editor

Steps to Reproduce

On startup

Expected Result

“Corrupt or missing files detected”
“Failed to open descriptor file … FortniteGame.uproject”

Observed Result

fORT-1152398

Affects Versions

4.27

Platform(s)

Windows