POL-1307 (UNKNOWN ERROR)

[RAIST]

What firewall are you running?

Basically, this. You'd be surprised how often these problems boil down to networking or security issues.

If you can run a network cable from this system directly to your modem, try that to see if it behaves (this is to rule out an issue with your router). If it still misbehaves while you are directly connected to your modem, then look at your local security (Windows or 3rd party Firewall, Internet Security or Anti-Virus software, etc.). If it behaves while some of this is bypassed/turned off, then that is where you need to focus on creating exceptions for FFXI. If it magically fixes it when you bypass your router, then you need to look at it's security options. It could be it's own firewall, or options with it's address translation (NAT)--consult your router's documentation for how to access the configuration pages to troubleshoot.

There are some older posts where a lot of this has been covered extensively...will see if I can find something to link here.

EDIT:
Here's a link that might help you get through diagnosing connectivity issues. Provided POL-1307 is not something account related (ie, a serverside issue SE needs to address), an installation problem (wrong client version, improper uninstall/reinstall procedures), or a hardware/driver related problem, then there is a strong possibility it is connectivity. Yes, this thread may be a wall of text, but the posts there as well as the threads linked there cover a wide range of things that can contribute to both inbound and outbound connectivity issues, which is often the root of problems:
http://forum.square-enix.com/ffxi/th...-4001-POL-0250