The issue occurs primarily when loading into a different zone via teleport. I found out that cancelling a teleport (via walking mid cast) can also cause the issue. I feel it may be an error linked to teleporting but it still does not occur every time. I have crashed on loading into Shirogane, Kugane, the Lochs, Old Gridania, and Central Thanalan.

I tried the clean boot as suggested, my pc actually has all startup processes disabled already as I dislike a bunch of programs coming on all at once. I was able to play without issue for a couple days until today. I crashed with the same error on trying to load into Shirogane from Kugane. After a few hours I tried logging in again and crashed upon attempting to load both my main character and alt character. Turning on/off DX9 mode still resulted in crashes. I did however find that loading my character on a separate PC, logging off, and loading on my pc allows me to login with no error...even in the same area (Loaded into fc plot in Shirogane and walked a couple steps before switching pcs) Hopefully something here may give insight into the cause of the error. I have talked to several others who are experiencing this exact error since the XV crossover started. It is quite discouraging to be interrupted in my gameplay by this but I enjoy the game and hope a solution can be found soon.
Thank you for your continued assistance!