You can't log in? Maybe your doing something a little off...
Make sure you have activated your account through email for a start. If your account is already activated, good for you! (I don't know how you would post on the forums if it wasn't activated...)
Make sure you are spelling your password/username correctly. Also be sure that caps lock isn't on. I had an issue where I couldn't log on because I had caps lock on. I do believe Feral Heart usernames/passwords are case sensitive. Maybe you put a capital letter at the beginning of your user/pass.
Is it saying cannot connect to server? Maybe the server is just down and you have to wait. Also check your internet connection.
If it is saying bad token, just refresh your game and try again later.
If all else fails, redownload the game, and try again.