I also receive this error, often daily, but never more than once or twice in a day. I've noticed the pattern is though, when I transition into new areas, or que with the duty finder. It always appears to happen when there is a situation where I will or could switch zones.

I also get "FFXIV has stopped responding" quite frequently too, where I'll be moving from an aetheryte crystal to a merchant to repair my gear and without warning, the game crashes, and I have to log back in. It's been a little frustrating but I'm so used to it now, I just go through the hoops of logging back in and carrying on.
I sure hope something is discovered to fix this, sounds like lots of people have the problem.

Cheers,