Thank you for sending me a copy of the project, NasteX. I’ll be honest and say that I’m not sure why exactly this fixed the problem but I found out how to package successfully with your project. Open the Project Settings and find the “List of maps to include in a packaged build” option and press the + button to add an entry. In your case, you’ll need to add 4 as it seems you have 4 maps. After doing this, add the maps from your content folder to this list. Once this is done, the packaging process should succeed without a problem.