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

Did anything change/update on your PC right before this happened? Is this on login or does the crash happen when playing the game?

A few things you can try:

-Switch to Directx 9 mode.
-Make sure that no other program or overlay (Geforce Experience, for example).
-Make sure your graphics card drivers are up to date.
-Perform a clean boot. Simply open the task manager and select the 'Start up' Tab. Disable everything here and restart the PC. This will make sure that no background processes are interfering with the game.

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