Unexpected error

Hello,
I keep getting the following error on login during the loading screen or shortly after:

An unexpected error has occurred. Exiting FINAL FANTASY XIV.
2021 - 11 - 27 _ 15:20

ntdll.dll+2E3CB
ntdll.dll+2B44D
atcuf64.dll+51C17
atcuf64.dll+4738
???+14B190110C7
???+1372
KERNELBASE.dll+6251D
???+6787

Can anyone help? I already updated my NVIDIA drivers

AVDefender or BitDefender Anti-virus software? A search on atcuf64.dll has hits for both of them. If so, maybe they need to be updated? You could try disabling your anti-virus software then launch the game and see if the problem still occurs. I have no idea if this will help, but hope it does.