Since the decision has been made to remove the springfiles>ZK server content bridge, users will no longer be able to download any map content ingame released after 11/29/2017. Consequently this renders these maps unplayable in multiplayer.
For the time being, you can still manually download maps in browser to Zero-K/Maps/ and play them in singleplayer. I'll be keeping track in this thread of all maps I've released since springfiles has been unsupported.