I can log in as usual and select my character, then I get to the loading screen. After a minute or so, I see "An unexpected error has occurred. Exiting FINAL FANTASY XIV.(17)" On a good day I only have to retry 2-5 times to get into the game. Usually if it takes more, I restore the game system settings and then try a couple of times before I finally load in.
If I do manage to load in, I then crash trying to change maps (entering estates, teleporting, etc) with the same error.

For the past few weeks it wasn't very frequent, but ever since 3.3 I've had this issue every time I launch the game.