Hey Ectelios!
I am looking into this issue now and it seems that all the content is available inside the pack after downloading from the launcher. If you could try and remove local content from your launcher for this pack. Once you do so, try re-downloading the pack once more and confirm if the content is still missing. If you are still having the same issue, please email us at marketplace-support@unrealengine.com for further assistance. We will get to the bottom of what might be causing this problem. 