Good afternoon and thank you for posting on the Final Fantasy XIV Technical Support Forums.

We apologize for not getting to your issue before. Can you submit a Final Fantasy XIV system report? Simply go to the 'Config' option on the Final Fantasy XIV launcher and to the right of 'System Information' click on 'Display.'

When the game does lock up, is it simply the game or does your entire computer stop working, requiring a reboot?

You mentioned it happens on and off, do you notice any patterns to the error (aside from it happening in major cities)?

We hope we can be of assistance in helping you enjoy the exciting world of Final Fantasy XIV!