A friend of mine wanted to try ffxiv again.
He had an acc long time ago with trial and has made a new.
But when he tried to install the game he received following errors:

Unable to complete version update.
[30435] [30415] [5] [19900] [5]
C:/Users/Name/Documents/My Games/FINAL FANTASY XIV - A Realm Reborn/downloads/ffxivupdater.exe

We have tried following solutions, but none has worked out:
1. Deleting and reinstalling
2. Allowing ffxivupdater thru Virus & Threat Protection and said solution by Aerissa on the ffxiv forum (https://forum.square-enix.com/ffxiv/threads/423011)