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Chunk Downloader Changed in UE5

I attempted to follow the Chunk Downloader example for UE5 but after packaging I can see there are new file types that are created in the Pak folder – these include the original .pak (although very small files) and .utoc and .ucas files. With these new file extensions and different file sizes how does one setup the build manifest txt file? Does it all still work similarly as before?

I am stuck on this as well. The .paks download but I get an error mounting…

LogChunkDownloader: Chunk 1001 mount requested (1 pak sequence).
LogChunkDownloader: Error: Unable to mount chunk 1001 (no FCoreDelegates::MountPak bound)

Has anyone had any success using Chunk Downloader in Unreal 5?

That happens when “Use Io Store” is enabled in the “Packaging” section of the project settings. Seems like it is something to do with the “Zen Loader” introduced in 4.26. When enabled it will brake the Chunk Downloader since it only supports the .pak file itself. We also can’t use pak signing since the .sig file is generated from it. Our best bet is hope for Epic to expand the Chunk Downloader to work with these other engine features so we may benefit from date temper prevention, faster loading and the Chunk Downloader itself.

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