Can't open UEFN session in 41.20

Summary

Pressing Load Session in UEFN editor does the usual loading animation, then instead of Fortnite opening a new tab appears called Session Inspector, and I wait for Fortnite to open up. After nearly 5 minutes of Fortnite not opening, an error displays saying “Server shut off due to no game client connecting in reserve window” and the session button is available to be pressed again. There is no validation error. I’ve tried opening the island about 6 times today to no avail.

Please select what you are reporting on:

Unreal Editor for Fortnite

What Type of Bug are you experiencing?

Matchmaking

Steps to Reproduce

Just press the Start Session button and wait

Expected Result

The map will validate, and after the starting load, Fortnite should open and load the player directly into the UEFN session.

Observed Result

The map will validate correctly, but Fortnite will not open. Instead, in a tab called Session Inspector, it will load for aproximately 5 minutes until an error pops up, reading along the lines of “Server was shut off due to no game client connecting in reserved window.” Fortnite will not open in its own tab.

Platform(s)

PC