The issue may be caused by the following:

• The specified account name (e-mail address) is already registered.

• A network error occurred.

• Entered the wrong confirmation code.

• The confirmation code has expired.

Check the following items:

• When the specified account name (e-mail address) is already registered

  Register another e-mail address as an account name.

• When a network error occurred

  Check that there are no errors with your network environment, and try again.

• When the wrong confirmation code is entered

  Go back to the point where you enter the confirmation code.

  Make sure to enter the confirmation code shown in the confirmation e-mail.

• When the confirmation code has expired

  Go back to the point where you enter an account name.

  A confirmation code has an expiration date. Enter the confirmation code as soon as you receive it in a notification e-mail.