Greetings fellow Eorzean,

The 90002 error is an error that appears usually when there is a connection issue or interference with the game's servers. I would recommend trying out the following troubleshooting steps to see if it helps with alleviating the issue:

In the Control Panel of the PC, please go to ‘Network and Internet’. Once there, select ‘Internet Options’ and adjust the following settings:
- Under the "General" tab, please delete ALL browser history.
- Under the "Security" tab, please move the slider to the lowest possible settings or no higher than "Medium"
- Under the "Privacy" tab, click “Advanced” and select ‘Accept’ under both First Party and Third Party Cookies.
- Under the "Advanced" tab, please make sure that "Allow software to run or install even if signature is invalid" is CHECKED.
- Make sure that all SSL and TLS (EXCEPT SSL 3.0) are CHECKED. [SSL 3.0 should be UNCHECKED]
- Hit "Apply" to save the settings, and then "OK, to close the Internet Options menu.
- Right-Click on the FFXIV launcher icon and select "Properties"
- Hit "Apply", then "OK" to save the changes.
- Please RESTART your PC after. Once your PC has been restarted, right-Click the FFXIV launcher icon once more and select "Run as Administrator".

Additionally, please make sure all background applications, including anti-virus programs, are disabled or closed to minimize game interference before attempting to log in.

We hope to be of assistance with this issue! Thank you for posting in the FINAL FANTASY XIV Technical Support Forums.