Black screen occurs when exiting a UEFN island and returning to the Fortnite lobby.

[Solved] Black screen when returning to lobby caused by K-Pop Warriors AI devices (UEFN)

Summary:
An infinite black screen occurred when returning to the Fortnite lobby after exiting a UEFN island. The issue was caused by a K-Pop Warriors AI device.

Environment:

  • Unreal Editor for Fortnite (UEFN)

  • Island using the K-Pop Warriors brand

Issue Description:
After leaving the island and returning to the lobby, Fortnite would get stuck on a black screen indefinitely. The game did not crash and no fatal error was shown.

Root Cause:
The issue was caused by the K-Pop Warriors Character Generator AI device.
Having this device in the project caused the session to fail when closing and returning to the lobby.

Final Solution:

  • Removed all K-Pop Warriors AI devices from the project.

Result:

  • The project now cooks and compiles correctly.

  • Entering and exiting the island works as expected.

  • The black screen no longer occurs when returning to the lobby.

Conclusion:
If a UEFN island using the K-Pop Warriors brand experiences a black screen when returning to the lobby, creators should review and remove K-Pop Warriors AI devices, especially the Character Generator, as they can cause critical issues when ending a session.