Go to Computer > Local Disk C > Program Files (x86) > PlayOnline > SquareEnix > FFXI > ROM > 0 >. Inside of that folder, take the 0.dat File and move it to your desk top. After you FULLY complete your Repair, you can delete it.
For Windower users (which should be everyone at this point) Open your PlayOnlineViewer Folder. For most people, this file will be located at. Computer > Local Disk C > Program Files (x86) > PlayOnline > SquareEnix > PlayOnlineViewer. Open the pol1.exe inside of your PlayOnlineViewer folder to update~
Right after you open it, there is a "Check Files" Tab on the left, click it.
On the next page there is a drop down menu, make sure it reads FFXI.
If for some reason you get some weird installation popup from windows before or right after this step, cancel it and proceed to the POL stuff. (I got it before so im sure some others players have to)
After you have FFXI on the drop menu, click check files. This could take 10-20 mins or a bit longer. After that's done, you will be asked to repair files. DO IT. This could take anywhere from 10 minutes to over an hour, so be patient. Once that's done, your good to go!