Update Native Problem

So i tried to open Minecraft - And it comes up with Updating Minecraft, Downloading Runtime. When it finished it came up with " Unable To update the minecraft native launcher " So i decided to try again. It happened again. So i decided to download a new Minecraft and update Java, I tried again and it still comes up with " Unable To update the minecraft native launcher "
How do i fix this?
On Macintosh by the way