Thank you for your report! We would like to look into this further, would you be able to submit a bug report using the form available here: Fortnite Creative
I noticed that the Item Placer devices suddenly have been removed from my map (9 devices) and when I launch the session is like the system still trying find them but I don’t have them in the files so I get this error.
If someone knows how to fix the problam please help me solve it