New Unreal Engine 5 DLC Packaging .PAK + .UTOC & .UCAS

Hello, does anyone know how to interact with DLC after Unreal 5 changed the packaging system from just a .PAK file to a small .PAK file along side a new large .UCAS file accompanied with a .UTOC file?

I have an app on UE4 with a working DLC system and on UE5 it is now different. I have read online you can disable “Use Io Store” to revert back to only .PAK files, but this is BROKEN in UE5 and it completely ignores if its disabled, and still packages it with all 3 files.

Waiting on Epic to fix this seems less reliable than simply learning how to interact with these new files. How do we use them? Does the user just need to download 3 files now instead of one? How does this work?

Thank you! This has now halted upgrading my app to UE5.


It’s not changed. It’s extended. To get back to a single pak, untick the use io store in project settings.


Thank you, I did this and it initially did not work, but I found out its because I was using the Project Launcher and it has its own IO Store setting that is on by default.

Thank you!

This does not answer the question, though.
How do you now package a separate content for IO store published build in a fashion similar to PAK workflow? I’ve tried cooking a chunk with Io store enable and it seems to be being read and mount by platform automatically, like old PAKs, however, none of the assets inside can be discovered and mount points all broken, it mounters /Game/Mods into “/” (???)


I am aware, I guess we must wait for Epic to explain or a tutorial online.

Did you have any luck with this in unreal 5?

I think pak files no longer available for 5.1. While IO settings disabled (by default) Engine generates ucas, utoc and a pak file. I wonder about patching the game with these files. Which files are going to change or will be overwritten? Are there anyone to share info about this topic?