Match versions: a world from a different game build may not load. Keep the server
on the same branch/version as the world's source.
default) and compress it.zip.universe/worldsdefault world folder (or whichever world you're replacing)..zip, then right-click it and choose Unarchive.universe/players, remove the existingplayers archive there.universe/worlds (not nested inside an extra subfolder), and that you removed thedefault.universe/players, or you replaced