If you try to build a project in the new Project Launcher UI in UE5.6 with the configuration:
“Shipping / Pak files / Compress Pak files / Cook content / your maps / Build the game / Archive build”,
you will get an error within the first few seconds.
I’ve been trying to figure out the reason for days. And I finally solved it!
Open Platforms → Legacy Project Launcher.
Find the profile you created in the new UI and click on its settings. What do we see here?
The answer is simple: in the new UI, the Package section is missing, and by default, it’s set to “Do not package”. This completely breaks the build process! Set it to “Package & store locally”, and you will now be able to build your project both from the old UI and the new UI.
Epic really needs to improve the new Project Launcher UI. This is terrible! It’s a nightmare! The absence of a whole section will break builds for many developers. I hope my post helps anyone who ran into this issue.