I also can't log in! For me L2.exe crashes after clicking on the login button. I downloaded the 2.0 client via torrent and the 2.0 patch, and it doesn't work. Also downloaded the 1.5 client to see if that version is working, but I can log in there without any problem. I attach the l2.log file.. As far as I can tell it says my username or password is not correct, but it's working everywhere else (in the 1.5 client too). I made a new account, but it's the same.
l2.log