Error Codes POL-5312 and POL-1158 cause updates to fail and so cannot play

[Elliander]

I reactivated my Final Fantasy XI and Final Fantasy XIV accounts via the Square Enix Accounts page. Afterwards I had no issues with logging into FFXIV, but I got repeated errors that kept FFXI from updating so I decided to uninstall my disc based installation and, since the discs are missing at the moment, I reinstalled by downloading the files from the Play Online website. The problem persists.

This is the problem:

After logging in successfully, I get the following error:

Friends List Communication Error
Error code:POL-5312
The Square Enix ID, Square Enix password, or one-time password entered is correct

This error of course makes no sense since there is no place to actually enter the Square Enix password.

After going to "Final Fantasy XI > Play > Play" there is a momentary freeze for a few minutes and then it lets me click "Update" and then it says "Downloading the latest version's information" then I get:

Version Update Communication Error
Error code:POL-1158
An unexpected error occurred.
Persistent problems can be reported from service & support.

I checked the website to make sure the server status is up of course, and it is. Since I first tried from a disc install, and then tried from a reinstall downloaded, I don't know what else I can try. Oh, in my last try, I reinstalled from download and then overwrite with a backup of the disc install before trying to update (seeing as how it would have less to download) and that didn't help either.

I also tried going into "Check Files" from PlayOnline, but unfortunately that only checks the files of PlayOnline Viewer and Tetra Master. It finds no problems with either, which is extra strange since Tetra Master no longer exists, I just happen to still have the installation files.

Frequency: Always (tried uninstall/reinstall)
Platform: PC; Homebuilt Computer

Intel i7-5820K CPU @ 3.30 GHz (4-core 8-threads) water cooled, 64 GB DDR 4 RAM, Nvidia 980 Ti water cooled, a solid state C drive with around 50 TB of magnetic drives, and 4 monitors.

OS: Windows 10 Professional 64-bit

ISP: Charter

Type of Internet Connection: Cable; 200 megabits per second.

PlayOnline Viewer Ver.1.18.15e

EDIT: This answer does not solve my problem as I have NEVER installed the steam version on my computer. Regardless, I did fully uninstall as the page suggests and reinstalled with the files it links to.

https://support.na.square-enix.com/f...id=58229&id=20