Fatal error loading map

Hey so I am getting a Fatal Error when loading my lobby map and need help fixing it.
So my maps go like this

Main Menu → Lobby Map → (Playable Levels 1-5)

Loading from one to the other is fine but when I execute [servertravel Lobby], all clients get a Fatal Error and the game crashes (they see the lobby for 0.1seconds before crashing).

This seems to only be the case when we test it on steam as when I try it in the editor or even packaged, it works fine.

This was not an issue for me a few days ago. I have tried duplicating the Lobby level and changing the servertravel command to the new map but clients still receive the same Error.
I don’t think its possible to look at the logs as the loading works fine in the editor.

I have tried for a few days now and cannot find a solution, can someone point me in the right direction ?