I posted a couple days ago that my game started crashing every day when they released patch 5.3. It had never crashed before that patch. Today I believe I have figured out what was causing the crashing for me. I discovered that I could not get through the sapphire weapon instance without crashing, I tried maybe a dozen times. So, I used this to test various possible fixes. Tried turning off gsync, tried unplugging my secondary monitor, tried changing various settings in the nvidia control panel all to no avail. Finally I tried limiting the framerate to 60fps in the nvidia control panel program specific 3D settings for FFXIV and I was able to get through the entire instance. I have a 165hz monitor. Normally FFXIV was only giving me maybe 120fps max, but I did notice that with the most recent update I was getting upwards of 160fps. At first I thought this was a good thing, that they had finally optimized the game to run properly on high refresh rate monitors. Now I'm thinking that's what was causing the game to crash. I'm going to try bumping the cap up to 120 to see how far I can push it without crashing, I can live with a framerate over 100.