This has happened before, approx. 1 month ago. Somehow someone is using the in-game social system to crash peoples clients. It is currently only happening on Gilgamesh(to my knowledge). The temporary fix is to set yourself to /busy so they cannot interact with you. You would need to somehow know the individual name to blist them for a more long term. Below is the link to the last time this had happened. Blist'ing this person fixed the problem for me. This is REAL. I don't know how they are doing but it is happening again.

When you log in, you will crash within a minute or two. My guess is someone is running a program that interacts at specific intervals.

http://forum.square-enix.com/ffxiv/t...FFXIV-Crashing


Here is a link to the most recent (today) issues. This is only happening to a handful of people that I know of.

http://forum.square-enix.com/ffxiv/t...ode-0xc0000005