Hi, I managed to fix this. I suspected that if i could reduce my graphics settings then the error would be resolved. After the reinstall i went to the config file and changed the graphics settings, saved and relaunched.

To edit your graphics config go to:

C:\Users\XXX\Documents\My Games\FINAL FANTASY XIV - A Realm Reborn

Right click on the FFXIV.cfg and open with Notepad.

Here you will see your graphics settings for the game. Change your resolution, fps, etc to the last settings you know worked. Some of the options have numbers next to them (0,1,2 or 3) usually 3 is the highest setting and 0 means turn off. I only changed a couple of them to 0 where i was sure that 0 meant off.

When you have made your changes, click Save.

Go back to your launcher and try again. Good luck!