Greetings Adventurer!

We would be happy to assist with your concern. Please try the following troubleshooting to see if this helps with the connection issues you are experiencing. Please make sure your fire wall or antivirus program is not interfering with the game. As you have already attempted the first step in this troubleshooting, we would like for you to attempt the rest to see if this helps with the connection 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

Try disabling background applications and do a clean boot by opening the task manager and selecting the “Start up” tab. Disable everything and then restart the PC.

Lastly, we suggest to power cycle the router by shutting down the Router and leaving the power supply unplugged for 5-10 minutes. 

- Flush DNS: Within the "Command Prompt" of the device, please type the command "ipconfig /flushdns".
- Reset TCP/IP: Also within the Command Prompt, type the command "netsh int ip reset" and then restart the computer.
- 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 do not see an improvement, please feel free to respond to this thread for further troubleshooting.

Thank you for visiting the FINAL FANTASY XIV Technical Support Forums!