Hello hirikara, Thank you for posting on the Final Fantasy XIV Technical Support Forums

We apologize for any inconvenience you may be experiencing. We would suggest lowering the graphic settings in game, as the intense graphics in dungeons can cause the crashing. We also suggest that the graphics card are using the latest drivers for the card. Should you be using Direct X 11 and experiencing the issue, we would suggest reverting back to Direct X 9 to see if the issue still persists. Also make sure your Graphics card drivers are updated to the latest version (alternatively, if you feel the graphics driver update caused the issue, you can try to install an older, more stable version). Also make sure that any program that provides and overlay is also disabled. For example, if you have an Nvidia card, the drivers may suggest installing Geforce Experience. As this may interfere with the game, we suggest leaving this disabled or uninstalled. Also, try disabling or closing all background applications/programs.

Hope to be of assistance.