If you remember when the game crashed, check the errors that occurred around that timestamp.

You'd specifically want to look for errors that mention display drivers, DX11, and other GPU related functions that XIV needs to run properly, as those are the usual culprits when it comes to crashes of this nature.

You might be in an awkward situation like me where the PC is crashing while gaming but not actually logging any errors, though (Which seems to imply it's an issue pertaining to the motherboard settings or something else that's out of the Windows event log's reach).