Fortnite keeps hanging when I click to launch a session

Summary

When I click to launch a session with Fortnite already open, Fortnite hangs about 75% of the time, but it does quickly reopen when matchmaking commences.

Please select what you are reporting on:

Unreal Editor for Fortnite

What Type of Bug are you experiencing?

Other

Steps to Reproduce

1.) Open UEFN on a fairly big project
2.) Click “Launch Session”
3.) See “This application [Fortnite] has hung. It will now close” message

Expected Result

Fortnite won’t hang when I click Launch Session.

Observed Result

Fortnite usually hangs and it must be reopened by the matchmaking for the session.

Platform(s)

PC

Additional Notes

The project I’m launching has 14k actors if that’s helpful.