You MUST put the correct username and password. You also must put your email that you signed up with. (This field does not update. This is just a saftey precaution) Lastly, you MUST select the game version you want, even if you have it set to a specific one.
IF YOU HAD USED TFACONNECT.ORG TO RESET YOUR PASSWORD, YOU MAY NEED TO USE THE PASSWORD YOU TRIED TO CHANGE IT TO FOR THIS TO WORK CORRECTLY!!