The Archivists

You’ve made contact with an Empire that carefully stores all their knowledge in a vast collection of archives, and downloaded a transmission of one such archive. Why can’t they communicate with the rest of the civilizations?

P.S. Our Galactic Nations contact has told us that some of your English puzzle answers will be useful here, but you will *not* need to use any translations of your puzzle answers. Additionally, you will need to use some things you've learned about the language through the various artifacts.