Good morning! Thank you for posting in the Final Fantasy XIV Technical Support Forums.

Please try the following troubleshooting suggestions as it may help resolve the issue:

Check to see if the following port ranges are opened on your router. You can contact your ISP and request they open them for you
▼TCP
54992 through 54994,
55006 through 55007,
55021 through 55040

- Delete the Patch Folder: Navigate to the folder using this path This PC > Docs > My Games> FFXIV ARR > Downloads > FFXIV patch (Use for either the version update error or cannot download patch files error)
Then either rename or remove the folder, the next time FINAL FANTASY XIV is launched, the client will repair the folder.
- Change local DNS: Please try changing the local DNS server to 8.8.8.8 and 8.8.4.4
- Delete local files with corrupted character data, please note this will not delete the associated characters.

If you have properly configured your router, and you are still experiencing these issues, our next suggestion is to bypass the router, and connect your console directly to your modem. Please ensure that you power down both the modem and the console for at least five minutes before attempting to connect to FINAL FANTASY XIV.

If you continue to receive these same errors when you are connected directly to the modem, then the problem lies with your ISP. We would recommend contacting them and advising them that one or more of the ports previously provided to you are being blocked or filtered, and that you do need access on these ports.

We hope we can be of assistance in helping you enjoy the exciting world of Final Fantasy XIV!