"A unexpected error has occurred. Exiting Final Fantasy XIV.(6d)" Error

[Pintsized]

So I tried a reinstall even though others have reported it doesn't fix it and indeed it doesn't.

I suspect it's video related as the error occurs right after clicking Play and before the screen goes black, and also as the only user-supplied solution in the closed thread was to run the game through an Nvidia tool but I don't have that and don't want it's hidden phone-home snooping.

The game's fine on two other PCs, so still need an SE response.