A friend of mine can no longer get onto the game because of this problem. We've played FFXIV together for years and she's never had a problem with crashes prior to today, so it's difficult not to point to the 4.0 patch.

It occurred today on her first visit to the new Rhalgr's Reach zone - within her first few moments in that zone she crashed with this error:



..and she continued to have the same sort of crash every time she tried to log back in. Worse, we're on Balmung and the 3000+ queues take a few hours to get through, meaning she only had time for a few attempts throughout today.

After switching from the DX11 client to the DX9 client at the launcher, she was finally able to get back on long enough to successfully escape the zone. Away from the expansion areas things seemed to be back to normal, and (hoping the switch to the DX9 client had permanently resolved the problem) she attempted to return to the Rhalgr's Reach zone. But after returning and moving through Rhalgr's Reach for less than a minute she crashed yet again with this error message:



Between the queues and her new crashing problem I get the sense that she's a heartbeat away from giving up on this game entirely. I'm at a loss as to what advice to give her; she actually has a beefier computer than mine and I'm not having any crashes.