If you install the first version available for mac and try to upload it , the game will ask you to download a newer version of the installer before you can proceed with the update. This answer doesn't resolve the problem I am having tho. For future references use your own technical support on the topic you are looking for.

For example like now:

FFXIV Launcher

A system error has occurred: -21.
http://frontier.ffxiv.com/version_3_...=2016-02-24-06