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

Unfortunately, this error is a bit vague so it's difficult to tell exactly what is causing it. However, I do have a few suggestions.

First, you can try 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. When you play the game, make sure to have no other programs running, especially overlays (Geforce Experience, Discord overlay, etc.).

Open the Nvidia Control Panel and going to 'Manage 3D Settings'. From here, select 'Program Settings' and select Final Fantasy XIV. You should see an option to select the GPU. Make sure it's set to your dedicated graphics card (it may be set to 'Auto' by default).

Set compatibility mode to Windows 7 Right-click on the ffxivboot.exe file and select ‘Properties.’ Then select the ‘Compatibility’ tab and choose Windows 7.

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